--- a/mobile/android/base/java/org/mozilla/gecko/GeckoApp.java
+++ b/mobile/android/base/java/org/mozilla/gecko/GeckoApp.java
@@ -155,16 +155,17 @@ public abstract class GeckoApp
 
     public static final String INTENT_REGISTER_STUMBLER_LISTENER = "org.mozilla.gecko.STUMBLER_REGISTER_LOCAL_LISTENER";
 
     public static final String EXTRA_STATE_BUNDLE          = "stateBundle";
 
     public static final String LAST_SELECTED_TAB           = "lastSelectedTab";
 
     public static final String PREFS_ALLOW_STATE_BUNDLE    = "allowStateBundle";
+    public static final String PREFS_FLASH_USAGE = "playFlashCount";
     public static final String PREFS_VERSION_CODE          = "versionCode";
     public static final String PREFS_WAS_STOPPED           = "wasStopped";
     public static final String PREFS_CRASHED_COUNT         = "crashedCount";
     public static final String PREFS_CLEANUP_TEMP_FILES    = "cleanupTempFiles";
 
     public static final String SAVED_STATE_IN_BACKGROUND   = "inBackground";
     public static final String SAVED_STATE_PRIVATE_SESSION = "privateSession";
 
@@ -819,16 +820,21 @@ public abstract class GeckoApp
         } else if ("Update:Check".equals(event)) {
             UpdateServiceHelper.checkForUpdate(this);
 
         } else if ("Update:Download".equals(event)) {
             UpdateServiceHelper.downloadUpdate(this);
 
         } else if ("Update:Install".equals(event)) {
             UpdateServiceHelper.applyUpdate(this);
+
+        } else if ("PluginHelper:playFlash".equals(event)) {
+            final SharedPreferences prefs = getSharedPreferences();
+            int count = prefs.getInt(PREFS_FLASH_USAGE, 0);
+            prefs.edit().putInt(PREFS_FLASH_USAGE,++count).apply();
         }
     }
 
     /**
      * @param permissions
      *        Array of JSON objects to represent site permissions.
      *        Example: { type: "offline-app", setting: "Store Offline Data", value: "Allow" }
      */
@@ -1236,16 +1242,17 @@ public abstract class GeckoApp
             }
         }
 
         // To prevent races, register startup events before launching the Gecko thread.
         EventDispatcher.getInstance().registerGeckoThreadListener(this,
             "Accessibility:Ready",
             "Gecko:Exited",
             "Gecko:Ready",
+            "PluginHelper:playFlash",
             null);
 
         EventDispatcher.getInstance().registerUiThreadListener(this,
             "Sanitize:Finished",
             null);
 
         GeckoThread.launch();
 
@@ -2331,16 +2338,17 @@ public abstract class GeckoApp
             super.onDestroy();
             return;
         }
 
         EventDispatcher.getInstance().unregisterGeckoThreadListener(this,
             "Accessibility:Ready",
             "Gecko:Exited",
             "Gecko:Ready",
+            "PluginHelper:playFlash",
             null);
 
         EventDispatcher.getInstance().unregisterUiThreadListener(this,
             "Sanitize:Finished",
             null);
 
         getAppEventDispatcher().unregisterGeckoThreadListener(this,
             "Accessibility:Event",

--- a/mobile/android/base/java/org/mozilla/gecko/telemetry/pingbuilders/TelemetryCorePingBuilder.java
+++ b/mobile/android/base/java/org/mozilla/gecko/telemetry/pingbuilders/TelemetryCorePingBuilder.java
@@ -11,17 +11,19 @@ import android.content.SharedPreferences
 import android.os.Build;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.annotation.WorkerThread;
 import android.text.TextUtils;
 
 import android.util.Log;
 import org.mozilla.gecko.AppConstants;
+import org.mozilla.gecko.GeckoApp;
 import org.mozilla.gecko.GeckoProfile;
+import org.mozilla.gecko.GeckoSharedPrefs;
 import org.mozilla.gecko.Locales;
 import org.mozilla.gecko.search.SearchEngine;
 import org.mozilla.gecko.sync.ExtendedJSONObject;
 import org.mozilla.gecko.telemetry.TelemetryPing;
 import org.mozilla.gecko.util.DateUtil;
 import org.mozilla.gecko.Experiments;
 import org.mozilla.gecko.util.StringUtils;
 
@@ -39,17 +41,17 @@ import java.util.concurrent.TimeUnit;
  */
 public class TelemetryCorePingBuilder extends TelemetryPingBuilder {
     private static final String LOGTAG = StringUtils.safeSubstring(TelemetryCorePingBuilder.class.getSimpleName(), 0, 23);
 
     // For legacy reasons, this preference key is not namespaced with "core".
     private static final String PREF_SEQ_COUNT = "telemetry-seqCount";
 
     private static final String NAME = "core";
-    private static final int VERSION_VALUE = 7; // For version history, see toolkit/components/telemetry/docs/core-ping.rst
+    private static final int VERSION_VALUE = 8; // For version history, see toolkit/components/telemetry/docs/core-ping.rst
     private static final String OS_VALUE = "Android";
 
     private static final String ARCHITECTURE = "arch";
     private static final String CAMPAIGN_ID = "campaignId";
     private static final String CLIENT_ID = "clientId";
     private static final String DEFAULT_SEARCH_ENGINE = "defaultSearch";
     private static final String DEVICE = "device";
     private static final String DISTRIBUTION_ID = "distributionId";
@@ -60,16 +62,17 @@ public class TelemetryCorePingBuilder ex
     private static final String PING_CREATION_DATE = "created";
     private static final String PROFILE_CREATION_DATE = "profileDate";
     private static final String SEARCH_COUNTS = "searches";
     private static final String SEQ = "seq";
     private static final String SESSION_COUNT = "sessions";
     private static final String SESSION_DURATION = "durations";
     private static final String TIMEZONE_OFFSET = "tz";
     private static final String VERSION_ATTR = "v";
+    private static final String FLASH_USAGE = "flashUsage";
 
     public TelemetryCorePingBuilder(final Context context) {
         initPayloadConstants(context);
     }
 
     private void initPayloadConstants(final Context context) {
         payload.put(VERSION_ATTR, VERSION_VALUE);
         payload.put(OS_ATTR, OS_VALUE);
@@ -85,16 +88,22 @@ public class TelemetryCorePingBuilder ex
 
         payload.put(ARCHITECTURE, AppConstants.ANDROID_CPU_ARCH);
         payload.put(DEVICE, deviceDescriptor);
         payload.put(LOCALE, Locales.getLanguageTag(Locale.getDefault()));
         payload.put(OS_VERSION, Integer.toString(Build.VERSION.SDK_INT)); // A String for cross-platform reasons.
         payload.put(PING_CREATION_DATE, pingCreationDateFormat.format(nowCalendar.getTime()));
         payload.put(TIMEZONE_OFFSET, DateUtil.getTimezoneOffsetInMinutesForGivenDate(nowCalendar));
         payload.putArray(EXPERIMENTS, Experiments.getActiveExperiments(context));
+        synchronized (this) {
+            SharedPreferences prefs = GeckoSharedPrefs.forApp(context);
+            final int count = prefs.getInt(GeckoApp.PREFS_FLASH_USAGE, 0);
+            payload.put(FLASH_USAGE, count);
+            prefs.edit().putInt(GeckoApp.PREFS_FLASH_USAGE, 0).apply();
+        }
     }
 
     @Override
     public String getDocType() {
         return NAME;
     }
 
     @Override

--- a/mobile/android/chrome/content/PluginHelper.js
+++ b/mobile/android/chrome/content/PluginHelper.js
@@ -1,13 +1,15 @@
 /* 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/. */
 "use strict";
 
+XPCOMUtils.defineLazyGetter(this, "GlobalEventDispatcher", () => EventDispatcher.instance);
+
 var PluginHelper = {
   showDoorHanger: function(aTab) {
     if (!aTab.browser)
       return;
 
     // Even though we may not end up showing a doorhanger, this flag
     // lets us know that we've tried to show a doorhanger.
     aTab.shouldShowPluginDoorhanger = false;
@@ -78,16 +80,20 @@ var PluginHelper = {
     if (!plugins || !plugins.length)
       return;
 
     plugins.forEach(this.playPlugin);
   },
 
   playPlugin: function(plugin) {
     let objLoadingContent = plugin.QueryInterface(Ci.nsIObjectLoadingContent);
+    let mimeType = objLoadingContent.actualType;
+    if (mimeType) {
+      GlobalEventDispatcher.sendRequest({ type: "PluginHelper:playFlash" });
+    }
     if (!objLoadingContent.activated)
       objLoadingContent.playPlugin();
   },
 
   getPluginPreference: function getPluginPreference() {
     let pluginDisable = Services.prefs.getBoolPref("plugin.disable");
     if (pluginDisable)
       return "0";

--- a/toolkit/components/telemetry/docs/data/core-ping.rst
+++ b/toolkit/components/telemetry/docs/data/core-ping.rst
@@ -50,16 +50,17 @@ Structure:
       "sessions": <integer>, // number of sessions since last upload
       "durations": <integer>, // combined duration, in seconds, of all
                                     // sessions since last upload
       "searches": <object>, // Optional, object of search use counts in the
                             // format: { "engine.source": <pos integer> }
                             // e.g.: { "yahoo.suggestion": 3, "other.listitem": 1 }
       "experiments": [<string>, /* … */], // Optional, array of identifiers
                                     // for the active experiments
+      "flashUsage": <integer>, // number of times flash plugin is played since last upload
     }
 
 Field details
 -------------
 
 device
 ~~~~~~
 The ``device`` field is filled in with information specified by the hardware
@@ -152,16 +153,17 @@ HTTP "Date" header
 This header is used to track the submission date of the core ping in the format
 specified by
 `rfc 2616 sec 14.18 <https://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.18>`_,
 et al (e.g. "Tue, 01 Feb 2011 14:00:00 GMT").
 
 
 Version history
 ---------------
+* v8: added ``flashUsage``
 * v7: added ``sessionCount`` & ``sessionDuration``
 * v6: added ``searches``
 * v5: added ``created`` & ``tz``
 * v4: ``profileDate`` will return package install time when times.json is not available
 * v3: added ``defaultSearch``
 * v2: added ``distributionId``
 * v1: initial version - shipped in `Fennec 45 <https://bugzilla.mozilla.org/show_bug.cgi?id=1205835>`_.