diff --git a/dom/plugins/ipc/PluginHangUIParent.cpp b/dom/plugins/ipc/PluginHangUIParent.cpp
index d41e5f48afb9..5e8e63d00b46 100644
--- a/dom/plugins/ipc/PluginHangUIParent.cpp
+++ b/dom/plugins/ipc/PluginHangUIParent.cpp
@@ -356,6 +356,7 @@ PluginHangUIParent::RecvUserResponse(const unsigned int& aResponse)
     mModule->TerminateChildProcess(mMainThreadMessageLoop);
     responseCode = 1;
   } else if(aResponse & HANGUI_USER_RESPONSE_CONTINUE) {
+    mModule->OnHangUIContinue();
     // User clicked Continue
     responseCode = 2;
   } else {
diff --git a/dom/plugins/ipc/PluginModuleParent.cpp b/dom/plugins/ipc/PluginModuleParent.cpp
index 96329772addf..dd1b203afe07 100755
--- a/dom/plugins/ipc/PluginModuleParent.cpp
+++ b/dom/plugins/ipc/PluginModuleParent.cpp
@@ -133,6 +133,7 @@ PluginModuleParent::PluginModuleParent(const char* aFilePath)
     , mNPNIface(nullptr)
     , mPlugin(nullptr)
     , mTaskFactory(MOZ_THIS_IN_INITIALIZER_LIST())
+    , mHangAnnotationFlags(0)
 #ifdef XP_WIN
     , mPluginCpuUsageOnHang()
     , mHangUIParent(nullptr)
@@ -160,6 +161,8 @@ PluginModuleParent::PluginModuleParent(const char* aFilePath)
 #ifdef MOZ_ENABLE_PROFILER_SPS
     InitPluginProfiling();
 #endif
+
+    mozilla::HangMonitor::RegisterAnnotator(*this);
 }
 
 PluginModuleParent::~PluginModuleParent()
@@ -203,6 +206,8 @@ PluginModuleParent::~PluginModuleParent()
         mHangUIParent = nullptr;
     }
 #endif
+
+    mozilla::HangMonitor::UnregisterAnnotator(*this);
 }
 
 #ifdef MOZ_CRASHREPORTER
@@ -224,20 +229,8 @@ PluginModuleParent::WriteExtraDataForMinidump(AnnotationTable& notes)
         filePos++;
     notes.Put(NS_LITERAL_CSTRING("PluginFilename"), CS(pluginFile.substr(filePos).c_str()));
 
-    nsCString pluginName;
-    nsCString pluginVersion;
-
-    nsRefPtr<nsPluginHost> ph = nsPluginHost::GetInst();
-    if (ph) {
-        nsPluginTag* tag = ph->TagForPlugin(mPlugin);
-        if (tag) {
-            pluginName = tag->mName;
-            pluginVersion = tag->mVersion;
-        }
-    }
-
-    notes.Put(NS_LITERAL_CSTRING("PluginName"), pluginName);
-    notes.Put(NS_LITERAL_CSTRING("PluginVersion"), pluginVersion);
+    notes.Put(NS_LITERAL_CSTRING("PluginName"), mPluginName);
+    notes.Put(NS_LITERAL_CSTRING("PluginVersion"), mPluginVersion);
 
     CrashReporterParent* crashReporter = CrashReporter();
     if (crashReporter) {
@@ -389,13 +382,52 @@ GetProcessCpuUsage(const InfallibleTArray<base::ProcessHandle>& processHandles,
 
 } // anonymous namespace
 
+#endif // #ifdef XP_WIN
+
+void
+PluginModuleParent::EnteredCxxStack()
+{
+    mHangAnnotationFlags |= kInPluginCall;
+}
+
 void
 PluginModuleParent::ExitedCxxStack()
 {
+    mHangAnnotationFlags = 0;
+#ifdef XP_WIN
     FinishHangUI();
+#endif
 }
 
-#endif // #ifdef XP_WIN
+/**
+ * This function is always called by the HangMonitor thread.
+ */
+void
+PluginModuleParent::AnnotateHang(mozilla::HangMonitor::HangAnnotations& aAnnotations)
+{
+    uint32_t flags = mHangAnnotationFlags;
+    if (flags) {
+        /* We don't actually annotate anything specifically for kInPluginCall;
+           we use it to determine whether to annotate other things. It will
+           be pretty obvious from the ChromeHang stack that we're in a plugin
+           call when the hang occurred. */
+        if (flags & kHangUIShown) {
+            aAnnotations.AddAnnotation(NS_LITERAL_STRING("HangUIShown"),
+                                       true);
+        }
+        if (flags & kHangUIContinued) {
+            aAnnotations.AddAnnotation(NS_LITERAL_STRING("HangUIContinued"),
+                                       true);
+        }
+        if (flags & kHangUIDontShow) {
+            aAnnotations.AddAnnotation(NS_LITERAL_STRING("HangUIDontShow"),
+                                       true);
+        }
+        aAnnotations.AddAnnotation(NS_LITERAL_STRING("pluginName"), mPluginName);
+        aAnnotations.AddAnnotation(NS_LITERAL_STRING("pluginVersion"),
+                                   mPluginVersion);
+    }
+}
 
 #ifdef MOZ_CRASHREPORTER_INJECTOR
 static bool
@@ -531,6 +563,23 @@ PluginModuleParent::TerminateChildProcess(MessageLoop* aMsgLoop)
         NS_WARNING("failed to kill subprocess!");
 }
 
+bool
+PluginModuleParent::GetPluginDetails(nsACString& aPluginName,
+                                     nsACString& aPluginVersion)
+{
+    nsRefPtr<nsPluginHost> host = nsPluginHost::GetInst();
+    if (!host) {
+        return false;
+    }
+    nsPluginTag* pluginTag = host->TagForPlugin(mPlugin);
+    if (!pluginTag) {
+        return false;
+    }
+    aPluginName = pluginTag->mName;
+    aPluginVersion = pluginTag->mVersion;
+    return true;
+}
+
 #ifdef XP_WIN
 void
 PluginModuleParent::EvaluateHangUIState(const bool aReset)
@@ -566,21 +615,6 @@ PluginModuleParent::EvaluateHangUIState(const bool aReset)
     SetChildTimeout(autoStopSecs);
 }
 
-bool
-PluginModuleParent::GetPluginName(nsAString& aPluginName)
-{
-    nsRefPtr<nsPluginHost> host = nsPluginHost::GetInst();
-    if (!host) {
-        return false;
-    }
-    nsPluginTag* pluginTag = host->TagForPlugin(mPlugin);
-    if (!pluginTag) {
-        return false;
-    }
-    CopyUTF8toUTF16(pluginTag->mName, aPluginName);
-    return true;
-}
-
 bool
 PluginModuleParent::LaunchHangUI()
 {
@@ -593,7 +627,12 @@ PluginModuleParent::LaunchHangUI()
             return false;
         }
         if (mHangUIParent->DontShowAgain()) {
-            return !mHangUIParent->WasLastHangStopped();
+            mHangAnnotationFlags |= kHangUIDontShow;
+            bool wasLastHangStopped = mHangUIParent->WasLastHangStopped();
+            if (!wasLastHangStopped) {
+                mHangAnnotationFlags |= kHangUIContinued;
+            }
+            return !wasLastHangStopped;
         }
         delete mHangUIParent;
         mHangUIParent = nullptr;
@@ -601,12 +640,9 @@ PluginModuleParent::LaunchHangUI()
     mHangUIParent = new PluginHangUIParent(this, 
             Preferences::GetInt(kHangUITimeoutPref, 0),
             Preferences::GetInt(kChildTimeoutPref, 0));
-    nsAutoString pluginName;
-    if (!GetPluginName(pluginName)) {
-        return false;
-    }
-    bool retval = mHangUIParent->Init(pluginName);
+    bool retval = mHangUIParent->Init(NS_ConvertUTF8toUTF16(mPluginName));
     if (retval) {
+        mHangAnnotationFlags |= kHangUIShown;
         /* Once the UI is shown we switch the timeout over to use 
            kChildTimeoutPref, allowing us to terminate a hung plugin 
            after kChildTimeoutPref seconds if the user doesn't respond to 
@@ -636,6 +672,12 @@ PluginModuleParent::FinishHangUI()
         }
     }
 }
+
+void
+PluginModuleParent::OnHangUIContinue()
+{
+    mHangAnnotationFlags |= kHangUIContinued;
+}
 #endif // XP_WIN
 
 #ifdef MOZ_CRASHREPORTER
@@ -1263,6 +1305,10 @@ PluginModuleParent::NPP_New(NPMIMEType pluginType, NPP instance,
         return NS_ERROR_FAILURE;
     }
 
+    if (mPluginName.IsEmpty()) {
+        GetPluginDetails(mPluginName, mPluginVersion);
+    }
+
     // create the instance on the other side
     InfallibleTArray<nsCString> names;
     InfallibleTArray<nsCString> values;
diff --git a/dom/plugins/ipc/PluginModuleParent.h b/dom/plugins/ipc/PluginModuleParent.h
index 91c0dcc1bf22..47f152af38bf 100644
--- a/dom/plugins/ipc/PluginModuleParent.h
+++ b/dom/plugins/ipc/PluginModuleParent.h
@@ -9,6 +9,7 @@
 
 #include "base/process.h"
 #include "mozilla/FileUtils.h"
+#include "mozilla/HangMonitor.h"
 #include "mozilla/PluginLibrary.h"
 #include "mozilla/plugins/ScopedMethodFactory.h"
 #include "mozilla/plugins/PluginProcessParent.h"
@@ -59,6 +60,7 @@ class PluginModuleParent
 #ifdef MOZ_CRASHREPORTER_INJECTOR
     , public CrashReporter::InjectorCrashCallback
 #endif
+    , public mozilla::HangMonitor::Annotator
 {
 private:
     typedef mozilla::PluginLibrary PluginLibrary;
@@ -112,9 +114,22 @@ public:
 
     void TerminateChildProcess(MessageLoop* aMsgLoop);
 
-#ifdef XP_WIN
-    void
+    virtual void
+    EnteredCxxStack() MOZ_OVERRIDE;
+
+    virtual void
     ExitedCxxStack() MOZ_OVERRIDE;
+
+    virtual void
+    AnnotateHang(mozilla::HangMonitor::HangAnnotations& aAnnotations) MOZ_OVERRIDE;
+
+#ifdef XP_WIN
+    /**
+     * Called by Plugin Hang UI to notify that the user has clicked continue.
+     * Used for chrome hang annotations.
+     */
+    void
+    OnHangUIContinue();
 #endif // XP_WIN
 
 protected:
@@ -287,6 +302,16 @@ private:
     nsString mBrowserDumpID;
     nsString mHangID;
     nsRefPtr<nsIObserver> mProfilerObserver;
+    enum HangAnnotationFlags
+    {
+        kInPluginCall = (1u << 0),
+        kHangUIShown = (1u << 1),
+        kHangUIContinued = (1u << 2),
+        kHangUIDontShow = (1u << 3)
+    };
+    Atomic<uint32_t> mHangAnnotationFlags;
+    nsCString mPluginName;
+    nsCString mPluginVersion;
 #ifdef XP_WIN
     InfallibleTArray<float> mPluginCpuUsageOnHang;
     PluginHangUIParent *mHangUIParent;
@@ -307,9 +332,6 @@ private:
     void
     EvaluateHangUIState(const bool aReset);
 
-    bool
-    GetPluginName(nsAString& aPluginName);
-
     /**
      * Launches the Plugin Hang UI.
      *
@@ -327,6 +349,9 @@ private:
     FinishHangUI();
 #endif
 
+    bool
+    GetPluginDetails(nsACString& aPluginName, nsACString& aPluginVersion);
+
 #ifdef MOZ_X11
     // Dup of plugin's X socket, used to scope its resources to this
     // object instead of the plugin process's lifetime