Add NavigationToFirstContentfulPaint UMA for ServiceWorker controlled pages.

third_party/WebKit/Source/core/loader/FrameLoader.cpp

Index: third_party/WebKit/Source/core/loader/FrameLoader.cpp
diff --git a/third_party/WebKit/Source/core/loader/FrameLoader.cpp b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
index b165a2e788363496aed321df4557f0904602bf14..117563a436cb7e320b792da3c6aa3820ad79f71a 100644
--- a/third_party/WebKit/Source/core/loader/FrameLoader.cpp
+++ b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
@@ -429,6 +429,10 @@ void FrameLoader::receivedFirstData()
 
     client()->dispatchDidCommitLoad(m_currentItem.get(), historyCommitType);
 
+    // didObserveLoadingBehavior() must be called after dispatchDidCommitLoad() is called for the metrics tracking logic to handle it properly.

[kinuko, 2016/04/26 13:15:43]

nit: could we / do we have assertion somewhere to make sure this?

[horo, 2016/04/27 02:30:15]

DocumentLoader::didObserveLoadingBehavior() has "ASSERT(m_state >= Committed)"
check.

https://chromium.googlesource.com/chromium/src/+/b4d6bf98e54db861b8d9adc7642c...

[kinuko, 2016/04/27 09:09:40]

I know, but we don't take the document loader path this case do we?

+    if (client()->isControlledByServiceWorker(*m_documentLoader))
+        client()->didObserveLoadingBehavior(WebLoadingBehaviorServiceWorkerControlled);
+
     TRACE_EVENT1("devtools.timeline", "CommitLoad", "data", InspectorCommitLoadEvent::data(m_frame));
     InspectorInstrumentation::didCommitLoad(m_frame, m_documentLoader.get());
     m_frame->page()->didCommitLoad(m_frame);