new file mode 100644
--- /dev/null
+++ b/media/gmp-clearkey/0.1/ClearKeyCencParser.cpp
@@ -0,0 +1,189 @@
+/*
+ * Copyright 2015, Mozilla Foundation and contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "ClearKeyCencParser.h"
+
+#include "mozilla/Assertions.h"
+#include "ArrayUtils.h"
+#include "BigEndian.h"
+#include <memory.h>
+#include <algorithm>
+#include <assert.h>
+#include <limits>
+
+// Stripped down version of mp4_demuxer::ByteReader, stripped down to make it
+// easier to link into ClearKey DLL and gtest.
+class ByteReader
+{
+public:
+  ByteReader(const uint8_t* aData, size_t aSize)
+    : mPtr(aData), mRemaining(aSize), mLength(aSize)
+  {
+  }
+
+  size_t Offset() const
+  {
+    return mLength - mRemaining;
+  }
+
+  size_t Remaining() const { return mRemaining; }
+
+  size_t Length() const { return mLength; }
+
+  bool CanRead8() const { return mRemaining >= 1; }
+
+  uint8_t ReadU8()
+  {
+    auto ptr = Read(1);
+    if (!ptr) {
+      MOZ_ASSERT(false);
+      return 0;
+    }
+    return *ptr;
+  }
+
+  bool CanRead32() const { return mRemaining >= 4; }
+
+  uint32_t ReadU32()
+  {
+    auto ptr = Read(4);
+    if (!ptr) {
+      MOZ_ASSERT(false);
+      return 0;
+    }
+    return mozilla::BigEndian::readUint32(ptr);
+  }
+
+  const uint8_t* Read(size_t aCount)
+  {
+    if (aCount > mRemaining) {
+      mRemaining = 0;
+      return nullptr;
+    }
+    mRemaining -= aCount;
+
+    const uint8_t* result = mPtr;
+    mPtr += aCount;
+
+    return result;
+  }
+
+  const uint8_t* Seek(size_t aOffset)
+  {
+    if (aOffset > mLength) {
+      MOZ_ASSERT(false);
+      return nullptr;
+    }
+
+    mPtr = mPtr - Offset() + aOffset;
+    mRemaining = mLength - aOffset;
+    return mPtr;
+  }
+
+private:
+  const uint8_t* mPtr;
+  size_t mRemaining;
+  const size_t mLength;
+};
+
+#define FOURCC(a,b,c,d) ((a << 24) + (b << 16) + (c << 8) + d)
+
+ // System ID identifying the cenc v2 pssh box format; specified at:
+ // https://dvcs.w3.org/hg/html-media/raw-file/tip/encrypted-media/cenc-format.html
+const uint8_t kSystemID[] = {
+  0x10, 0x77, 0xef, 0xec, 0xc0, 0xb2, 0x4d, 0x02,
+  0xac, 0xe3, 0x3c, 0x1e, 0x52, 0xe2, 0xfb, 0x4b
+};
+
+void
+ParseCENCInitData(const uint8_t* aInitData,
+                  uint32_t aInitDataSize,
+                  std::vector<std::vector<uint8_t>>& aOutKeyIds)
+{
+  ByteReader reader(aInitData, aInitDataSize);
+  while (reader.CanRead32()) {
+    // Box size. For the common system Id, ignore this, as some useragents
+    // handle invalid box sizes.
+    const size_t start = reader.Offset();
+    const size_t size = reader.ReadU32();
+    if (size > std::numeric_limits<size_t>::max() - start) {
+      // Ensure 'start + size' calculation below can't overflow.
+      return;
+    }
+    const size_t end = std::min<size_t>(start + size, reader.Length());
+
+    // PSSH box type.
+    if (!reader.CanRead32()) {
+      return;
+    }
+    uint32_t box = reader.ReadU32();
+    if (box != FOURCC('p','s','s','h')) {
+      reader.Seek(std::max<size_t>(reader.Offset(), end));
+      continue;
+    }
+
+    // 1 byte version, 3 bytes flags.
+    if (!reader.CanRead32()) {
+      return;
+    }
+    uint8_t version = reader.ReadU8();
+    if (version != 1) {
+      // Ignore pssh boxes with wrong version.
+      reader.Seek(std::max<size_t>(reader.Offset(), end));
+      continue;
+    }
+    reader.Read(3); // skip flags.
+
+    // SystemID
+    const uint8_t* sid = reader.Read(sizeof(kSystemID));
+    if (!sid) {
+      // Insufficinet bytes to read SystemID.
+      return;
+    }
+    if (memcmp(kSystemID, sid, sizeof(kSystemID))) {
+      // Ignore pssh boxes with wrong system ID.
+      reader.Seek(std::max<size_t>(reader.Offset(), end));
+      continue;
+    }
+
+    if (!reader.CanRead32()) {
+      return;
+    }
+    uint32_t kidCount = reader.ReadU32();
+
+    for (uint32_t i = 0; i < kidCount; i++) {
+      if (reader.Remaining() < CLEARKEY_KEY_LEN) {
+        // Not enough remaining to read key.
+        return;
+      }
+      const uint8_t* kid = reader.Read(CLEARKEY_KEY_LEN);
+      aOutKeyIds.push_back(std::vector<uint8_t>(kid, kid + CLEARKEY_KEY_LEN));
+    }
+
+    // Size of extra data. EME CENC format spec says datasize should
+    // always be 0. We explicitly read the datasize, in case the box
+    // size was 0, so that we get to the end of the box.
+    if (!reader.CanRead32()) {
+      return;
+    }
+    reader.ReadU32();
+
+    // Jump forwards to the end of the box, skipping any padding.
+    if (size) {
+      reader.Seek(end);
+    }
+  }
+}

new file mode 100644
--- /dev/null
+++ b/media/gmp-clearkey/0.1/ClearKeyCencParser.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2015, Mozilla Foundation and contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __ClearKeyCencParser_h__
+#define __ClearKeyCencParser_h__
+
+#include <stdint.h>
+#include <vector>
+
+#define CLEARKEY_KEY_LEN ((size_t)16)
+
+void
+ParseCENCInitData(const uint8_t* aInitData,
+                  uint32_t aInitDataSize,
+                  std::vector<std::vector<uint8_t>>& aOutKeyIds);
+
+#endif

--- a/media/gmp-clearkey/0.1/ClearKeySession.cpp
+++ b/media/gmp-clearkey/0.1/ClearKeySession.cpp
@@ -14,16 +14,17 @@
  * limitations under the License.
  */
 
 #include "BigEndian.h"
 #include "ClearKeyDecryptionManager.h"
 #include "ClearKeySession.h"
 #include "ClearKeyUtils.h"
 #include "ClearKeyStorage.h"
+#include "ClearKeyCencParser.h"
 #include "gmp-task-utils.h"
 #include "gmp-api/gmp-decryption.h"
 #include <assert.h>
 #include <string.h>
 
 using namespace mozilla;
 
 ClearKeySession::ClearKeySession(const std::string& aSessionId,
@@ -55,17 +56,17 @@ void
 ClearKeySession::Init(uint32_t aCreateSessionToken,
                       uint32_t aPromiseId,
                       const std::string& aInitDataType,
                       const uint8_t* aInitData, uint32_t aInitDataSize)
 {
   CK_LOGD("ClearKeySession::Init");
 
   if (aInitDataType == "cenc") {
-    ClearKeyUtils::ParseCENCInitData(aInitData, aInitDataSize, mKeyIds);
+    ParseCENCInitData(aInitData, aInitDataSize, mKeyIds);
   } else if (aInitDataType == "keyids") {
     std::string sessionType;
     ClearKeyUtils::ParseKeyIdsInitData(aInitData, aInitDataSize, mKeyIds, sessionType);
     if (sessionType != ClearKeyUtils::SessionTypeToString(mSessionType)) {
       const char message[] = "Session type specified in keyids init data doesn't match session type.";
       mCallback->RejectPromise(aPromiseId, kGMPAbortError, message, strlen(message));
       return;
     }

--- a/media/gmp-clearkey/0.1/ClearKeyUtils.cpp
+++ b/media/gmp-clearkey/0.1/ClearKeyUtils.cpp
@@ -25,25 +25,16 @@
 #include "ArrayUtils.h"
 #include <assert.h>
 #include <memory.h>
 #include "BigEndian.h"
 #include "openaes/oaes_lib.h"
 
 using namespace std;
 
-#define FOURCC(a,b,c,d) ((a << 24) + (b << 16) + (c << 8) + d)
-
-// System ID identifying the cenc v2 pssh box format; specified at:
-// https://dvcs.w3.org/hg/html-media/raw-file/tip/encrypted-media/cenc-format.html
-const uint8_t kSystemID[] = {
-  0x10, 0x77, 0xef, 0xec, 0xc0, 0xb2, 0x4d, 0x02,
-  0xac, 0xe3, 0x3c, 0x1e, 0x52, 0xe2, 0xfb, 0x4b
-};
-
 void
 CK_Log(const char* aFmt, ...)
 {
   va_list ap;
 
   va_start(ap, aFmt);
   vprintf(aFmt, ap);
   va_end(ap);
@@ -127,74 +118,16 @@ EncodeBase64Web(vector<uint8_t> aBinary,
     assert(idx < MOZ_ARRAY_LENGTH(sAlphabet)); // out of bounds index for 'sAlphabet'
     out[i] = sAlphabet[idx];
   }
 
   return true;
 }
 
 /* static */ void
-ClearKeyUtils::ParseCENCInitData(const uint8_t* aInitData,
-                                 uint32_t aInitDataSize,
-                                 vector<KeyId>& aOutKeyIds)
-{
-  using mozilla::BigEndian;
-
-  uint32_t size = 0;
-  for (uint32_t offset = 0; offset + sizeof(uint32_t) < aInitDataSize; offset += size) {
-    const uint8_t* data = aInitData + offset;
-    size = BigEndian::readUint32(data); data += sizeof(uint32_t);
-
-    CK_LOGD("Looking for pssh at offset %u", offset);
-
-    if (size + offset > aInitDataSize) {
-      CK_LOGE("Box size %u overflows init data buffer", size);
-      return;
-    }
-
-    if (size < 36) {
-      // Too small to be a cenc2 pssh box
-      continue;
-    }
-
-    uint32_t box = BigEndian::readUint32(data); data += sizeof(uint32_t);
-    if (box != FOURCC('p','s','s','h')) {
-      CK_LOGE("ClearKey CDM passed non-pssh initData");
-      return;
-    }
-
-    uint32_t head = BigEndian::readUint32(data); data += sizeof(uint32_t);
-    CK_LOGD("Got version %u pssh box, length %u", head & 0xff, size);
-
-    if ((head >> 24) != 1) {
-      // Ignore pssh boxes with wrong version
-      CK_LOGD("Ignoring pssh box with wrong version");
-      continue;
-    }
-
-    if (memcmp(kSystemID, data, sizeof(kSystemID))) {
-      // Ignore pssh boxes with wrong system ID
-      continue;
-    }
-    data += sizeof(kSystemID);
-
-    uint32_t kidCount = BigEndian::readUint32(data); data += sizeof(uint32_t);
-    if (data + kidCount * CLEARKEY_KEY_LEN > aInitData + aInitDataSize) {
-      CK_LOGE("pssh key IDs overflow init data buffer");
-      return;
-    }
-
-    for (uint32_t i = 0; i < kidCount; i++) {
-      aOutKeyIds.push_back(KeyId(data, data + CLEARKEY_KEY_LEN));
-      data += CLEARKEY_KEY_LEN;
-    }
-  }
-}
-
-/* static */ void
 ClearKeyUtils::MakeKeyRequest(const vector<KeyId>& aKeyIDs,
                               string& aOutRequest,
                               GMPSessionType aSessionType)
 {
   assert(aKeyIDs.size() && aOutRequest.empty());
 
   aOutRequest.append("{\"kids\":[");
   for (size_t i = 0; i < aKeyIDs.size(); i++) {

--- a/media/gmp-clearkey/0.1/ClearKeyUtils.h
+++ b/media/gmp-clearkey/0.1/ClearKeyUtils.h
@@ -18,18 +18,16 @@
 #define __ClearKeyUtils_h__
 
 #include <stdint.h>
 #include <string>
 #include <vector>
 #include <assert.h>
 #include "gmp-api/gmp-decryption.h"
 
-#define CLEARKEY_KEY_LEN ((size_t)16)
-
 #if 0
 void CK_Log(const char* aFmt, ...);
 #define CK_LOGE(...) CK_Log(__VA_ARGS__)
 #define CK_LOGD(...) CK_Log(__VA_ARGS__)
 #define CK_LOGW(...) CK_Log(__VA_ARGS__)
 #else
 #define CK_LOGE(...)
 #define CK_LOGD(...)
@@ -49,20 +47,16 @@ struct KeyIdPair
 };
 
 class ClearKeyUtils
 {
 public:
   static void DecryptAES(const std::vector<uint8_t>& aKey,
                          std::vector<uint8_t>& aData, std::vector<uint8_t>& aIV);
 
-  static void ParseCENCInitData(const uint8_t* aInitData,
-                                uint32_t aInitDataSize,
-                                std::vector<Key>& aOutKeyIds);
-
   static bool ParseKeyIdsInitData(const uint8_t* aInitData,
                                   uint32_t aInitDataSize,
                                   std::vector<KeyId>& aOutKeyIds,
                                   std::string& aOutSessionType);
 
   static void MakeKeyRequest(const std::vector<KeyId>& aKeyIds,
                              std::string& aOutRequest,
                              GMPSessionType aSessionType);

--- a/media/gmp-clearkey/0.1/gtest/TestClearKeyUtils.cpp
+++ b/media/gmp-clearkey/0.1/gtest/TestClearKeyUtils.cpp
@@ -5,16 +5,17 @@
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "gtest/gtest.h"
 #include <algorithm>
 #include <stdint.h>
 #include <vector>
 
 #include "../ClearKeyBase64.cpp"
+#include "../ClearKeyCencParser.cpp"
 #include "../ArrayUtils.h"
 
 
 using namespace std;
 
 struct B64Test {
   const char* b64;
   uint8_t raw[16];
@@ -68,8 +69,168 @@ TEST(ClearKey, DecodeBase64KeyOrId) {
     if (test.shouldPass) {
       EXPECT_EQ(v.size(), 16u);
       for (size_t k = 0; k < 16; k++) {
         EXPECT_EQ(v[k], test.raw[k]);
       }
     }
   }
 }
+
+// This is the CENC initData from Google's web-platform tests.
+// https://github.com/w3c/web-platform-tests/blob/master/encrypted-media/Google/encrypted-media-utils.js#L50
+const uint8_t gGoogleWPTCencInitData[] = {
+  0x00, 0x00, 0x00, 0x00,                          // size = 0
+  0x70, 0x73, 0x73, 0x68,                          // 'pssh'
+  0x01,                                            // version = 1
+  0x00, 0x00, 0x00,                                // flags
+  0x10, 0x77, 0xEF, 0xEC, 0xC0, 0xB2, 0x4D, 0x02,  // Common SystemID
+  0xAC, 0xE3, 0x3C, 0x1E, 0x52, 0xE2, 0xFB, 0x4B,
+  0x00, 0x00, 0x00, 0x01,                          // key count
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,  // key
+  0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
+  0x00, 0x00, 0x00, 0x00                           // datasize
+};
+
+// Example CENC initData from the EME spec format registry:
+// https://w3c.github.io/encrypted-media/format-registry/initdata/cenc.html
+const uint8_t gW3SpecExampleCencInitData[] = {
+  0x00, 0x00, 0x00, 0x4c, 0x70, 0x73, 0x73, 0x68, // BMFF box header (76 bytes, 'pssh')
+  0x01, 0x00, 0x00, 0x00,                         // Full box header (version = 1, flags = 0)
+  0x10, 0x77, 0xef, 0xec, 0xc0, 0xb2, 0x4d, 0x02, // SystemID
+  0xac, 0xe3, 0x3c, 0x1e, 0x52, 0xe2, 0xfb, 0x4b,
+  0x00, 0x00, 0x00, 0x02,                         // KID_count (2)
+  0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, // First KID ("0123456789012345")
+  0x38, 0x39, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35,
+  0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, // Second KID ("ABCDEFGHIJKLMNOP")
+  0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x50,
+  0x00, 0x00, 0x00, 0x00                         // Size of Data (0)
+};
+
+// Invalid box size, would overflow if used.
+const uint8_t gOverflowBoxSize[] = {
+  0xff, 0xff, 0xff, 0xff,                          // size = UINT32_MAX
+};
+
+// Invalid box size, but retrievable data.
+const uint8_t gMalformedCencInitData[] = {
+  0x00, 0x00, 0xff, 0xff,                          // size = too big a number
+  0x70, 0x73, 0x73, 0x68,                          // 'pssh'
+  0x01,                                            // version = 1
+  0xff, 0xff, 0xff,                                // flags
+  0x10, 0x77, 0xEF, 0xEC, 0xC0, 0xB2, 0x4D, 0x02,  // Common SystemID
+  0xAC, 0xE3, 0x3C, 0x1E, 0x52, 0xE2, 0xFB, 0x4B,
+  0xff, 0xff, 0xff, 0xff,                          // key count = UINT32_MAX
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,  // key
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff                           // datasize
+};
+
+// Non PSSH box, followed by Non common SystemID PSSH, followed by common SystemID PSSH box.
+const uint8_t gLeadingNonCommonCencInitData[] = {
+  0x00, 0x00, 0x00, 0x09,                          // size = 9
+  0xff, 0xff, 0xff, 0xff,                          // something other than 'pssh'
+  0xff,                                            // odd number of bytes of garbage to throw off the parser
+
+  0x00, 0x00, 0x00, 0x5c,                          // size = 92
+  0x70, 0x73, 0x73, 0x68,                          // 'pssh'
+  0x01,                                            // version = 1
+  0x00, 0x00, 0x00,                                // flags
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,  // Invalid SystemID
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,  // Some data to pad out the box.
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+
+  // gW3SpecExampleCencInitData
+  0x00, 0x00, 0x00, 0x4c, 0x70, 0x73, 0x73, 0x68, // BMFF box header (76 bytes, 'pssh')
+  0x01, 0x00, 0x00, 0x00,                         // Full box header (version = 1, flags = 0)
+  0x10, 0x77, 0xef, 0xec, 0xc0, 0xb2, 0x4d, 0x02, // SystemID
+  0xac, 0xe3, 0x3c, 0x1e, 0x52, 0xe2, 0xfb, 0x4b,
+  0x00, 0x00, 0x00, 0x02,                         // KID_count (2)
+  0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, // First KID ("0123456789012345")
+  0x38, 0x39, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35,
+  0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, // Second KID ("ABCDEFGHIJKLMNOP")
+  0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x50,
+  0x00, 0x00, 0x00, 0x00                         // Size of Data (0)
+};
+
+const uint8_t gNonPSSHBoxZeroSize[] = {
+  0x00, 0x00, 0x00, 0x00,                          // size = 0
+  0xff, 0xff, 0xff, 0xff,                          // something other than 'pssh'
+};
+
+// Two lots of the google init data. To ensure we handle
+// multiple boxes with size 0.
+const uint8_t g2xGoogleWPTCencInitData[] = {
+  0x00, 0x00, 0x00, 0x00,                          // size = 0
+  0x70, 0x73, 0x73, 0x68,                          // 'pssh'
+  0x01,                                            // version = 1
+  0x00, 0x00, 0x00,                                // flags
+  0x10, 0x77, 0xEF, 0xEC, 0xC0, 0xB2, 0x4D, 0x02,  // Common SystemID
+  0xAC, 0xE3, 0x3C, 0x1E, 0x52, 0xE2, 0xFB, 0x4B,
+  0x00, 0x00, 0x00, 0x01,                          // key count
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,  // key
+  0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
+  0x00, 0x00, 0x00, 0x00,                          // datasize
+
+  0x00, 0x00, 0x00, 0x00,                          // size = 0
+  0x70, 0x73, 0x73, 0x68,                          // 'pssh'
+  0x01,                                            // version = 1
+  0x00, 0x00, 0x00,                                // flags
+  0x10, 0x77, 0xEF, 0xEC, 0xC0, 0xB2, 0x4D, 0x02,  // Common SystemID
+  0xAC, 0xE3, 0x3C, 0x1E, 0x52, 0xE2, 0xFB, 0x4B,
+  0x00, 0x00, 0x00, 0x01,                          // key count
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,  // key
+  0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
+  0x00, 0x00, 0x00, 0x00                           // datasize  
+};
+
+TEST(ClearKey, ParseCencInitData) {
+  std::vector<std::vector<uint8_t>> keyIds;
+
+  ParseCENCInitData(gGoogleWPTCencInitData, MOZ_ARRAY_LENGTH(gGoogleWPTCencInitData), keyIds);
+  EXPECT_EQ(keyIds.size(), 1u);
+  EXPECT_EQ(keyIds[0].size(), 16u);
+  EXPECT_EQ(memcmp(&keyIds[0].front(), &gGoogleWPTCencInitData[32], 16), 0);
+
+  keyIds.clear();
+  ParseCENCInitData(gW3SpecExampleCencInitData, MOZ_ARRAY_LENGTH(gW3SpecExampleCencInitData), keyIds);
+  EXPECT_EQ(keyIds.size(), 2u);
+  EXPECT_EQ(keyIds[0].size(), 16u);
+  EXPECT_EQ(memcmp(&keyIds[0].front(), &gW3SpecExampleCencInitData[32], 16), 0);
+  EXPECT_EQ(memcmp(&keyIds[1].front(), &gW3SpecExampleCencInitData[48], 16), 0);
+
+  keyIds.clear();
+  ParseCENCInitData(gOverflowBoxSize, MOZ_ARRAY_LENGTH(gOverflowBoxSize), keyIds);
+  EXPECT_EQ(keyIds.size(), 0u);
+
+  keyIds.clear();
+  ParseCENCInitData(gMalformedCencInitData, MOZ_ARRAY_LENGTH(gMalformedCencInitData), keyIds);
+  EXPECT_EQ(keyIds.size(), 1u);
+  EXPECT_EQ(keyIds[0].size(), 16u);
+  EXPECT_EQ(memcmp(&keyIds[0].front(), &gMalformedCencInitData[32], 16), 0);
+
+  keyIds.clear();
+  ParseCENCInitData(gLeadingNonCommonCencInitData, MOZ_ARRAY_LENGTH(gLeadingNonCommonCencInitData), keyIds);
+  EXPECT_EQ(keyIds.size(), 2u);
+  EXPECT_EQ(keyIds[0].size(), 16u);
+  EXPECT_EQ(memcmp(&keyIds[0].front(), &gW3SpecExampleCencInitData[32], 16), 0);
+  EXPECT_EQ(memcmp(&keyIds[1].front(), &gW3SpecExampleCencInitData[48], 16), 0);
+
+  keyIds.clear();
+  ParseCENCInitData(gNonPSSHBoxZeroSize, MOZ_ARRAY_LENGTH(gNonPSSHBoxZeroSize), keyIds);
+  EXPECT_EQ(keyIds.size(), 0u);
+
+  keyIds.clear();
+  ParseCENCInitData(g2xGoogleWPTCencInitData, MOZ_ARRAY_LENGTH(g2xGoogleWPTCencInitData), keyIds);
+  EXPECT_EQ(keyIds.size(), 2u);
+  EXPECT_EQ(keyIds[0].size(), 16u);
+  EXPECT_EQ(keyIds[1].size(), 16u);
+  EXPECT_EQ(memcmp(&keyIds[0].front(), &g2xGoogleWPTCencInitData[32], 16), 0);
+  EXPECT_EQ(memcmp(&keyIds[1].front(), &g2xGoogleWPTCencInitData[84], 16), 0);
+
+}

--- a/media/gmp-clearkey/0.1/moz.build
+++ b/media/gmp-clearkey/0.1/moz.build
@@ -8,16 +8,17 @@ SharedLibrary('clearkey')
 
 FINAL_TARGET = 'dist/bin/gmp-clearkey/0.1'
 
 FINAL_TARGET_PP_FILES += ['clearkey.info.in']
 
 UNIFIED_SOURCES += [
     'ClearKeyAsyncShutdown.cpp',
     'ClearKeyBase64.cpp',
+    'ClearKeyCencParser.cpp',
     'ClearKeyDecryptionManager.cpp',
     'ClearKeyPersistence.cpp',
     'ClearKeySession.cpp',
     'ClearKeySessionManager.cpp',
     'ClearKeyStorage.cpp',
     'ClearKeyUtils.cpp',
     'gmp-clearkey.cpp',
 ]