Revert of Make LoadMonitoringExtensionHostQueue remove itself as an ExtensionHost observer at the...

extensions/browser/extension_host.cc

Index: extensions/browser/extension_host.cc
diff --git a/extensions/browser/extension_host.cc b/extensions/browser/extension_host.cc
index df9248912921d0c31a5ec790b4cf799e5f92d465..bbf51ef4913b41b8d784b07c8eae28e7ed6eebad 100644
--- a/extensions/browser/extension_host.cc
+++ b/extensions/browser/extension_host.cc
@@ -58,7 +58,7 @@
       extension_id_(extension->id()),
       browser_context_(site_instance->GetBrowserContext()),
       render_view_host_(nullptr),
-      has_loaded_once_(false),
+      did_stop_loading_(false),
       document_element_available_(false),
       initial_url_(url),
       extension_function_dispatcher_(browser_context_, this),
@@ -92,7 +92,6 @@
     UMA_HISTOGRAM_LONG_TIMES("Extensions.EventPageActiveTime2",
                              load_start_->Elapsed());
   }
-
   content::NotificationService::current()->Notify(
       extensions::NOTIFICATION_EXTENSION_HOST_DESTROYED,
       content::Source<BrowserContext>(browser_context_),
@@ -102,16 +101,11 @@
   FOR_EACH_OBSERVER(DeferredStartRenderHostObserver,
                     deferred_start_render_host_observer_list_,
                     OnDeferredStartRenderHostDestroyed(this));
-
-  // Remove ourselves from the queue as late as possible (before effectively
-  // destroying self, but after everything else) so that queues that are
-  // monitoring lifetime get a chance to see stop-loading events.
   delegate_->GetExtensionHostQueue()->Remove(this);
-
-  // Deliberately stop observing |host_contents_| because its destruction
-  // events (like DidStopLoading, it turns out) can call back into
-  // ExtensionHost re-entrantly, when anything declared after |host_contents_|
-  // has already been destroyed.
+  // Immediately stop observing |host_contents_| because its destruction events
+  // (like DidStopLoading, it turns out) can call back into ExtensionHost
+  // re-entrantly, when anything declared after |host_contents_| has already
+  // been destroyed.
   content::WebContentsObserver::Observe(nullptr);
 }
 
@@ -225,7 +219,7 @@
 }
 
 bool ExtensionHost::IsBackgroundPage() const {
-  DCHECK_EQ(extension_host_type_, VIEW_TYPE_EXTENSION_BACKGROUND_PAGE);
+  DCHECK(extension_host_type_ == VIEW_TYPE_EXTENSION_BACKGROUND_PAGE);
   return true;
 }
 
@@ -274,23 +268,35 @@
 }
 
 void ExtensionHost::DidStopLoading(content::RenderViewHost* render_view_host) {
-  // Only record UMA for the first load. Subsequent loads will likely behave
-  // quite different, and it's first load we're most interested in.
-  if (!has_loaded_once_)
-    RecordStopLoadingUMA();
-  has_loaded_once_ = true;
+  bool notify = !did_stop_loading_;
+  did_stop_loading_ = true;
   OnDidStopLoading();
-  content::NotificationService::current()->Notify(
-      extensions::NOTIFICATION_EXTENSION_HOST_DID_STOP_LOADING,
-      content::Source<BrowserContext>(browser_context_),
-      content::Details<ExtensionHost>(this));
-  FOR_EACH_OBSERVER(DeferredStartRenderHostObserver,
-                    deferred_start_render_host_observer_list_,
-                    OnDeferredStartRenderHostDidStopLoading(this));
+  if (notify) {
+    CHECK(load_start_.get());
+    if (extension_host_type_ == VIEW_TYPE_EXTENSION_BACKGROUND_PAGE) {
+      if (extension_ && BackgroundInfo::HasLazyBackgroundPage(extension_)) {
+        UMA_HISTOGRAM_MEDIUM_TIMES("Extensions.EventPageLoadTime2",
+                                   load_start_->Elapsed());
+      } else {
+        UMA_HISTOGRAM_MEDIUM_TIMES("Extensions.BackgroundPageLoadTime2",
+                                   load_start_->Elapsed());
+      }
+    } else if (extension_host_type_ == VIEW_TYPE_EXTENSION_POPUP) {
+      UMA_HISTOGRAM_MEDIUM_TIMES("Extensions.PopupLoadTime2",
+                                 load_start_->Elapsed());
+    }
+    content::NotificationService::current()->Notify(
+        extensions::NOTIFICATION_EXTENSION_HOST_DID_STOP_LOADING,
+        content::Source<BrowserContext>(browser_context_),
+        content::Details<ExtensionHost>(this));
+    FOR_EACH_OBSERVER(DeferredStartRenderHostObserver,
+                      deferred_start_render_host_observer_list_,
+                      OnDeferredStartRenderHostDidStopLoading(this));
+  }
 }
 
 void ExtensionHost::OnDidStopLoading() {
-  DCHECK_EQ(extension_host_type_, VIEW_TYPE_EXTENSION_BACKGROUND_PAGE);
+  DCHECK(extension_host_type_ == VIEW_TYPE_EXTENSION_BACKGROUND_PAGE);
   // Nothing to do for background pages.
 }
 
@@ -455,20 +461,4 @@
   return view_type == extensions::VIEW_TYPE_EXTENSION_BACKGROUND_PAGE;
 }
 
-void ExtensionHost::RecordStopLoadingUMA() {
-  CHECK(load_start_.get());
-  if (extension_host_type_ == VIEW_TYPE_EXTENSION_BACKGROUND_PAGE) {
-    if (extension_ && BackgroundInfo::HasLazyBackgroundPage(extension_)) {
-      UMA_HISTOGRAM_MEDIUM_TIMES("Extensions.EventPageLoadTime2",
-                                 load_start_->Elapsed());
-    } else {
-      UMA_HISTOGRAM_MEDIUM_TIMES("Extensions.BackgroundPageLoadTime2",
-                                 load_start_->Elapsed());
-    }
-  } else if (extension_host_type_ == VIEW_TYPE_EXTENSION_POPUP) {
-    UMA_HISTOGRAM_MEDIUM_TIMES("Extensions.PopupLoadTime2",
-                               load_start_->Elapsed());
-  }
-}
-
 }  // namespace extensions