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

components/html_viewer/html_document.cc

Index: components/html_viewer/html_document.cc
diff --git a/components/html_viewer/html_document.cc b/components/html_viewer/html_document.cc
index 3d3a30312f8d2bcd0d25fe810d12bdd4513cd578..f699c86d98701db95c399f2552d0422493e08587 100644
--- a/components/html_viewer/html_document.cc
+++ b/components/html_viewer/html_document.cc
@@ -19,6 +19,7 @@
 #include "components/html_viewer/geolocation_client_impl.h"
 #include "components/html_viewer/global_state.h"
 #include "components/html_viewer/media_factory.h"
+#include "components/html_viewer/stats_collection_controller.h"
 #include "components/html_viewer/web_layer_tree_view_impl.h"
 #include "components/html_viewer/web_storage_namespace_impl.h"
 #include "components/html_viewer/web_url_loader_impl.h"
@@ -247,6 +248,9 @@ void HTMLDocument::Load(URLResponsePtr response) {
         new DevToolsAgentImpl(main_frame, html_document_app_->shell()));
   }
 
+  startup_performance_data_collector_ =
+      StatsCollectionController::Install(main_frame, html_document_app_);
+
   GURL url(response->url);
 
   WebURLRequestExtraData* extra_data = new WebURLRequestExtraData;
@@ -398,6 +402,13 @@ void HTMLDocument::didAddMessageToConsole(
           << message.text.utf8();
 }
 
+void HTMLDocument::didHandleOnloadEvents(blink::WebLocalFrame* frame) {
+  if (startup_performance_data_collector_.get()) {

[yzshen1, 2015/08/17 05:46:38]

nit: ".get()" is not necessary for null-check. (I think it is preferred by our
style guide that way?)

Besides, although it is not a concern here, in some cases it affects performance
too: 
Using ".get()" forces the InterfacePtr to setup router and handler watching for
the message pipe handle, if it is not set up yet. On the other hand, using "if
(startup_performance_data_collector_)" only checks whether it holds a valid
message pipe handle.

[msw, 2015/08/17 21:25:50]

Done; thanks for the extra info.

+    startup_performance_data_collector_->SetFirstWebContentsMainFrameLoadTime(

[yzshen1, 2015/08/17 05:46:38]

Do you think we should comment on why we call this for every onload event? (And
similarly for line 431)

[msw, 2015/08/17 21:25:50]

The mojom explains that only the first time is recorded, but in the interest of
performance I added static flags in these functions.

+        base::Time::Now().ToInternalValue());
+  }
+}
+
 void HTMLDocument::didFinishLoad(blink::WebLocalFrame* frame) {
   // TODO(msw): Notify AxProvider clients of updates on child frame loads.
   did_finish_load_ = true;
@@ -415,6 +426,13 @@ void HTMLDocument::didNavigateWithinPage(
     navigator_host_->DidNavigateLocally(history_item.urlString().utf8());
 }
 
+void HTMLDocument::didFirstVisuallyNonEmptyLayout(blink::WebLocalFrame* frame) {
+  if (startup_performance_data_collector_) {
+    startup_performance_data_collector_->SetFirstVisuallyNonEmptyLayoutTime(
+        base::Time::Now().ToInternalValue());
+  }
+}
+
 blink::WebEncryptedMediaClient* HTMLDocument::encryptedMediaClient() {
   return global_state_->media_factory()->GetEncryptedMediaClient();
 }