--- a/gfx/thebes/gfxDWriteCommon.h
+++ b/gfx/thebes/gfxDWriteCommon.h
@@ -9,17 +9,16 @@
 // Mozilla includes
 #include "nscore.h"
 #include "nsIServiceManager.h"
 #include "nsCOMPtr.h"
 #include "cairo-features.h"
 #include "gfxFontConstants.h"
 #include "nsTArray.h"
 #include "gfxWindowsPlatform.h"
-#include "nsIUUIDGenerator.h"
 
 #include <windows.h>
 #include <dwrite.h>
 
 static inline DWRITE_FONT_STRETCH
 DWriteFontStretchFromStretch(int16_t aStretch) 
 {
     switch (aStretch) {

--- a/gfx/thebes/gfxDWriteFontList.cpp
+++ b/gfx/thebes/gfxDWriteFontList.cpp
@@ -13,16 +13,17 @@
 #include "nsServiceManagerUtils.h"
 #include "nsCharSeparatedTokenizer.h"
 #include "mozilla/Preferences.h"
 #include "mozilla/Telemetry.h"
 #include "nsDirectoryServiceUtils.h"
 #include "nsDirectoryServiceDefs.h"
 #include "nsAppDirectoryServiceDefs.h"
 #include "nsISimpleEnumerator.h"
+#include "gfXUtils.h"
 
 #include "gfxGDIFontList.h"
 
 #include "nsIWindowsRegKey.h"
 
 #include "harfbuzz/hb.h"
 
 using namespace mozilla;

--- a/gfx/thebes/gfxFontUtils.cpp
+++ b/gfx/thebes/gfxFontUtils.cpp
@@ -2,27 +2,27 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "mozilla/ArrayUtils.h"
 #include "mozilla/BinarySearch.h"
 
 #include "gfxFontUtils.h"
+#include "gfxUtils.h"
 
 #include "nsServiceManagerUtils.h"
 
 #include "mozilla/dom/EncodingUtils.h"
 #include "mozilla/Preferences.h"
 #include "mozilla/Services.h"
 #include "mozilla/BinarySearch.h"
 #include "mozilla/Snprintf.h"
 
 #include "nsCOMPtr.h"
-#include "nsIUUIDGenerator.h"
 #include "nsIUnicodeDecoder.h"
 
 #include "harfbuzz/hb.h"
 
 #include "plbase64.h"
 #include "mozilla/Logging.h"
 
 #define LOG(log, args) MOZ_LOG(gfxPlatform::GetLog(log), \
@@ -858,27 +858,17 @@ void gfxFontUtils::GetPrefsFontList(cons
 // produce a unique font name that is (1) a valid Postscript name and (2) less
 // than 31 characters in length.  Using AddFontMemResourceEx on Windows fails 
 // for names longer than 30 characters in length.
 
 #define MAX_B64_LEN 32
 
 nsresult gfxFontUtils::MakeUniqueUserFontName(nsAString& aName)
 {
-    nsCOMPtr<nsIUUIDGenerator> uuidgen =
-      do_GetService("@mozilla.org/uuid-generator;1");
-    NS_ENSURE_TRUE(uuidgen, NS_ERROR_OUT_OF_MEMORY);
-
-    nsID guid;
-
-    NS_ASSERTION(sizeof(guid) * 2 <= MAX_B64_LEN, "size of nsID has changed!");
-
-    nsresult rv = uuidgen->GenerateUUIDInPlace(&guid);
-    NS_ENSURE_SUCCESS(rv, rv);
-
+    nsID guid = gfxUtils::GenerateUUID();
     char guidB64[MAX_B64_LEN] = {0};
 
     if (!PL_Base64Encode(reinterpret_cast<char*>(&guid), sizeof(guid), guidB64))
         return NS_ERROR_FAILURE;
 
     // all b64 characters except for '/' are allowed in Postscript names, so convert / ==> -
     char *p;
     for (p = guidB64; *p; p++) {

--- a/gfx/thebes/gfxUtils.cpp
+++ b/gfx/thebes/gfxUtils.cpp
@@ -7,16 +7,17 @@
 
 #include "cairo.h"
 #include "gfxContext.h"
 #include "gfxEnv.h"
 #include "gfxImageSurface.h"
 #include "gfxPlatform.h"
 #include "gfxDrawable.h"
 #include "imgIEncoder.h"
+#include "mozilla/DebugOnly.h"
 #include "mozilla/Base64.h"
 #include "mozilla/dom/ImageEncoder.h"
 #include "mozilla/dom/WorkerPrivate.h"
 #include "mozilla/dom/WorkerRunnable.h"
 #include "mozilla/gfx/2D.h"
 #include "mozilla/gfx/DataSurfaceHelpers.h"
 #include "mozilla/gfx/Logging.h"
 #include "mozilla/Maybe.h"
@@ -33,16 +34,17 @@
 #include "nsServiceManagerUtils.h"
 #include "yuv_convert.h"
 #include "ycbcr_to_rgb565.h"
 #include "GeckoProfiler.h"
 #include "ImageContainer.h"
 #include "ImageRegion.h"
 #include "gfx2DGlue.h"
 #include "gfxPrefs.h"
+#include "nsIUUIDGenerator.h"
 
 #ifdef XP_WIN
 #include "gfxWindowsPlatform.h"
 #endif
 
 using namespace mozilla;
 using namespace mozilla::image;
 using namespace mozilla::layers;
@@ -1558,16 +1560,29 @@ gfxUtils::ThreadSafeGetFeatureStatus(con
     }
 
     return runnable->GetNSResult();
   }
 
   return gfxInfo->GetFeatureStatus(feature, failureId, status);
 }
 
+/* static */ nsID
+gfxUtils::GenerateUUID()
+{
+  nsCOMPtr<nsIUUIDGenerator> uuidgen =
+      do_GetService("@mozilla.org/uuid-generator;1");
+  MOZ_ASSERT(uuidgen, "Couldn't get UUID generator");
+
+  nsID val;
+  DebugOnly<nsresult> rv = uuidgen->GenerateUUIDInPlace(&val);
+  MOZ_ASSERT(NS_SUCCEEDED(rv), "Generating UUID failed");
+  return val;
+}
+
 /* static */ bool
 gfxUtils::DumpDisplayList() {
   return gfxPrefs::LayoutDumpDisplayList() ||
          (gfxPrefs::LayoutDumpDisplayListContent() && XRE_IsContentProcess());
 }
 
 FILE *gfxUtils::sDumpPaintFile = stderr;
 

--- a/gfx/thebes/gfxUtils.h
+++ b/gfx/thebes/gfxUtils.h
@@ -295,16 +295,21 @@ public:
                                                int32_t* status);
 
     /**
      * Copy to the clipboard as a PNG encoded Data URL.
      */
     static void CopyAsDataURI(SourceSurface* aSourceSurface);
     static void CopyAsDataURI(DrawTarget* aDT);
 
+    /**
+     * Generate a UUID
+     */
+    static nsID GenerateUUID();
+
     static bool DumpDisplayList();
 
     static FILE* sDumpPaintFile;
 };
 
 namespace mozilla {
 namespace gfx {