Add stats collection for telemetry startup.warm.blank_page test.

components/html_viewer/html_document.h

Index: components/html_viewer/html_document.h
diff --git a/components/html_viewer/html_document.h b/components/html_viewer/html_document.h
index 926e503cfcbdad67da868f85cb1c7d4ff084e2a3..ce5825454a7098f63a295d81a0eb556831bb917e 100644
--- a/components/html_viewer/html_document.h
+++ b/components/html_viewer/html_document.h
@@ -9,6 +9,7 @@
 
 #include "base/callback.h"
 #include "base/macros.h"
+#include "base/observer_list.h"
 #include "components/html_viewer/ax_provider_impl.h"
 #include "components/html_viewer/touch_handler.h"
 #include "components/view_manager/public/cpp/view_manager_client_factory.h"
@@ -41,6 +42,7 @@ class AxProviderImpl;
 class DevToolsAgentImpl;
 class GeolocationClientImpl;
 class GlobalState;
+class StatsCollectionController;
 class WebLayerTreeViewImpl;
 
 // A view for a single HTML document.
@@ -71,6 +73,18 @@ class HTMLDocument : public blink::WebViewClient,
     DeleteCallback delete_callback;
   };
 
+  class Observer {

[sky, 2015/08/12 23:54:36]

I'm hoping to nuke HTMLDocument soon. Can you move this to HTMLDOcumentOOPIF?
You may want to push this to HTMLFrame. And move to its own header.

[msw, 2015/08/14 23:20:34]

Nothing actually uses StatsCollectionController::GetTabLoadTiming (the only
reason this observation was needed), so it's removed.

+   public:
+    explicit Observer(HTMLDocument* html_document);
+    virtual ~Observer();
+    virtual void DidStartLoading() {}
+    virtual void DidStopLoading() {}
+    HTMLDocument* html_document() const { return html_document_; }
+   private:
+    HTMLDocument* html_document_;
+    DISALLOW_COPY_AND_ASSIGN(Observer);
+  };
+
   // Load a new HTMLDocument with |response|.
   // |html_document_app| is the application this app was created in, and
   // |connection| the specific connection triggering this new instance.
@@ -80,6 +94,9 @@ class HTMLDocument : public blink::WebViewClient,
   // Deletes this object.
   void Destroy();
 
+  void AddObserver(HTMLDocument::Observer* observer);

[sky, 2015/08/12 23:54:36]

Can these two be private since Observer takes care of it for you?

[msw, 2015/08/14 23:20:34]

Removed.

+  void RemoveObserver(HTMLDocument::Observer* observer);
+
   blink::WebView* web_view() const { return web_view_; }
 
  protected:
@@ -114,10 +131,14 @@ class HTMLDocument : public blink::WebViewClient,
                                       const blink::WebString& source_name,
                                       unsigned source_line,
                                       const blink::WebString& stack_trace);
+  virtual void didStartLoading(bool toDifferentDocument);

[yzshen1, 2015/08/13 15:59:11]

naming style: to_different_document, so it is consistent with the other methods.

[msw, 2015/08/14 23:20:34]

Removed.

+  virtual void didStopLoading();
+  virtual void didHandleOnloadEvents(blink::WebLocalFrame* frame);
   virtual void didFinishLoad(blink::WebLocalFrame* frame);
   virtual void didNavigateWithinPage(blink::WebLocalFrame* frame,
                                      const blink::WebHistoryItem& history_item,
                                      blink::WebHistoryCommitType commit_type);
+  virtual void didFirstVisuallyNonEmptyLayout(blink::WebLocalFrame* frame);
   virtual blink::WebEncryptedMediaClient* encryptedMediaClient();
 
  private:
@@ -189,6 +210,9 @@ class HTMLDocument : public blink::WebViewClient,
 
   DeleteCallback delete_callback_;
 
+  StatsCollectionController* stats_collection_controller_;

[yzshen1, 2015/08/13 15:59:11]

Please comment about ownership and when it is null/non-null, etc.

[msw, 2015/08/14 23:20:34]

Hmm, holding gin::Wrappable objects on the heap isn't supported:
https://code.google.com/p/chromium/codesearch#chromium/src/gin/handle.h&l=12
So I've replaced this with a StartupPerformanceDataCollectorPtr.

+  base::ObserverList<HTMLDocument::Observer> observers_;
+
   DISALLOW_COPY_AND_ASSIGN(HTMLDocument);
 };