--- a/dom/plugins/ipc/PluginModuleParent.cpp
+++ b/dom/plugins/ipc/PluginModuleParent.cpp
@@ -119,16 +119,21 @@ mozilla::plugins::SetupBridge(uint32_t a
     PluginModuleChromeParent::ClearInstantiationFlag();
     RefPtr<nsPluginHost> host = nsPluginHost::GetInst();
     RefPtr<nsNPAPIPlugin> plugin;
     *rv = host->GetPluginForContentProcess(aPluginId, getter_AddRefs(plugin));
     if (NS_FAILED(*rv)) {
         return true;
     }
     PluginModuleChromeParent* chromeParent = static_cast<PluginModuleChromeParent*>(plugin->GetLibrary());
+    /*
+     *  We can't accumulate BLOCKED_ON_PLUGIN_MODULE_INIT_MS until here because
+     *  its histogram key is not available until *after* NP_Initialize.
+     */
+    chromeParent->AccumulateModuleInitBlockedTime();
     *rv = chromeParent->GetRunID(runID);
     if (NS_FAILED(*rv)) {
         return true;
     }
     if (chromeParent->IsStartingAsync()) {
         chromeParent->SetContentParent(aContentParent);
     }
     if (!aForceBridgeNow && chromeParent->IsStartingAsync() &&
@@ -396,23 +401,26 @@ PluginModuleContentParent::LoadModule(ui
      * message. Before it sends its response, it sends a message to create
      * PluginModuleParent instance. That message is handled by
      * PluginModuleContentParent::Initialize, which saves the instance in
      * its module mapping. We fetch it from there after LoadPlugin finishes.
      */
     dom::ContentChild* cp = dom::ContentChild::GetSingleton();
     nsresult rv;
     uint32_t runID;
+    TimeStamp sendLoadPluginStart = TimeStamp::Now();
     if (!cp->SendLoadPlugin(aPluginId, &rv, &runID) ||
         NS_FAILED(rv)) {
         return nullptr;
     }
+    TimeStamp sendLoadPluginEnd = TimeStamp::Now();
 
     PluginModuleContentParent* parent = mapping->GetModule();
     MOZ_ASSERT(parent);
+    parent->mTimeBlocked += (sendLoadPluginEnd - sendLoadPluginStart);
 
     if (!mapping->IsChannelOpened()) {
         // mapping is linked into PluginModuleMapping::sModuleListHead and is
         // needed later, so since this function is returning successfully we
         // forget it here.
         mapping.forget();
     }
 
@@ -2621,36 +2629,45 @@ class nsCaseInsensitiveUTF8StringArrayCo
 {
 public:
   template<class A, class B>
   bool Equals(const A& a, const B& b) const {
     return a.Equals(b.get(), nsCaseInsensitiveUTF8StringComparator());
   }
 };
 
+void
+PluginModuleParent::AccumulateModuleInitBlockedTime()
+{
+    if (mPluginName.IsEmpty()) {
+        GetPluginDetails();
+    }
+    Telemetry::Accumulate(Telemetry::BLOCKED_ON_PLUGIN_MODULE_INIT_MS,
+                          GetHistogramKey(),
+                          static_cast<uint32_t>(mTimeBlocked.ToMilliseconds()));
+    mTimeBlocked = TimeDuration();
+}
+
 nsresult
 PluginModuleParent::NPP_NewInternal(NPMIMEType pluginType, NPP instance,
                                     uint16_t mode,
                                     InfallibleTArray<nsCString>& names,
                                     InfallibleTArray<nsCString>& values,
                                     NPSavedData* saved, NPError* error)
 {
     if (mPluginName.IsEmpty()) {
         GetPluginDetails();
         InitQuirksModes(nsDependentCString(pluginType));
         /** mTimeBlocked measures the time that the main thread has been blocked
          *  on plugin module initialization. As implemented, this is the sum of
          *  plugin-container launch + toolhelp32 snapshot + NP_Initialize.
          *  We don't accumulate its value until here because the plugin info
-         *  is not available until *after* NP_Initialize.
+         *  for its histogram key is not available until *after* NP_Initialize.
          */
-        Telemetry::Accumulate(Telemetry::BLOCKED_ON_PLUGIN_MODULE_INIT_MS,
-                              GetHistogramKey(),
-                              static_cast<uint32_t>(mTimeBlocked.ToMilliseconds()));
-        mTimeBlocked = TimeDuration();
+        AccumulateModuleInitBlockedTime();
     }
 
     nsCaseInsensitiveUTF8StringArrayComparator comparator;
     NS_NAMED_LITERAL_CSTRING(srcAttributeName, "src");
     auto srcAttributeIndex = names.IndexOf(srcAttributeName, 0, comparator);
     nsAutoCString srcAttribute;
     if (srcAttributeIndex != names.NoIndex) {
         srcAttribute = values[srcAttributeIndex];

--- a/dom/plugins/ipc/PluginModuleParent.h
+++ b/dom/plugins/ipc/PluginModuleParent.h
@@ -131,16 +131,18 @@ public:
     void ProcessRemoteNativeEventsInInterruptCall() override;
 
     virtual bool WaitForIPCConnection() { return true; }
 
     nsCString GetHistogramKey() const {
         return mPluginName + mPluginVersion;
     }
 
+    void AccumulateModuleInitBlockedTime();
+
     virtual nsresult GetRunID(uint32_t* aRunID) override;
     virtual void SetHasLocalInstance() override {
         mHadLocalInstance = true;
     }
 
     int GetQuirks() { return mQuirks; }
 
 protected: