[Binding] [UMA] Add a UMA to track time spent in WindowProxy::initialize

third_party/WebKit/Source/bindings/core/v8/WindowProxy.cpp

Index: third_party/WebKit/Source/bindings/core/v8/WindowProxy.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/WindowProxy.cpp b/third_party/WebKit/Source/bindings/core/v8/WindowProxy.cpp
index 7b6d9481037862a9ae2daf4096626ba8ec1464c3..d91a9dae7b335ca963241c53f85495a56d1af6f1 100644
--- a/third_party/WebKit/Source/bindings/core/v8/WindowProxy.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/WindowProxy.cpp
@@ -61,6 +61,7 @@
 #include "platform/weborigin/SecurityOrigin.h"
 #include "public/platform/Platform.h"
 #include "wtf/Assertions.h"
+#include "wtf/CurrentTime.h"
 #include "wtf/OwnPtr.h"
 #include "wtf/StringExtras.h"
 #include "wtf/text/CString.h"
@@ -225,6 +226,7 @@ bool WindowProxy::initialize()
 {
     TRACE_EVENT0("v8", "WindowProxy::initialize");
     TRACE_EVENT_SCOPED_SAMPLING_STATE("blink", "InitializeWindow");
+    double startTime = currentTimeMS();

[kouhei (in TOK), 2016/05/24 09:08:12]

use monotonicallyIncreasingTime() instead of currentTimeMS, or better, just use 
SCOPED_BLINK_UMA_HISTOGRAM_TIMER :)

[peria, 2016/05/24 09:36:24]

Oh, I misunderstood the last argument of CustomCountHistogram.
Done.

 
     ScriptForbiddenScope::AllowUserAgentScript allowScript;
 
@@ -269,6 +271,10 @@ bool WindowProxy::initialize()
         MainThreadDebugger::instance()->contextCreated(m_scriptState.get(), frame, origin);
         frame->loader().client()->didCreateScriptContext(context, m_world->extensionGroup(), m_world->worldId());
     }
+
+    double endTime = currentTimeMS();
+    DEFINE_STATIC_LOCAL(CustomCountHistogram, initializeHistogram, ("Blink.Binding.InitializeWindowProxy", 0, 200, 5));
+    initializeHistogram.count(endTime - startTime);
     return true;
 }