DevTools: Switch to using fast stack iterator to collect stacks during timeline recording.

third_party/WebKit/Source/core/inspector/InspectorTraceEvents.cpp

Index: third_party/WebKit/Source/core/inspector/InspectorTraceEvents.cpp
diff --git a/third_party/WebKit/Source/core/inspector/InspectorTraceEvents.cpp b/third_party/WebKit/Source/core/inspector/InspectorTraceEvents.cpp
index 675101a641777e58a9c95989725c3d43b9668423..ff93b8d7bd78379aa29bdfd9178db34c2c4738a9 100644
--- a/third_party/WebKit/Source/core/inspector/InspectorTraceEvents.cpp
+++ b/third_party/WebKit/Source/core/inspector/InspectorTraceEvents.cpp
@@ -33,6 +33,7 @@
 #include "wtf/Vector.h"
 #include "wtf/text/TextPosition.h"
 #include <inttypes.h>
+#include <v8-profiler.h>
 #include <v8.h>
 
 namespace blink {
@@ -52,9 +53,13 @@ void setCallStack(TracedValue* value)
         traceCategoryEnabled = TRACE_EVENT_API_GET_CATEGORY_GROUP_ENABLED(TRACE_DISABLED_BY_DEFAULT("devtools.timeline.stack"));
     if (!*traceCategoryEnabled)
         return;
-    RefPtr<ScriptCallStack> scriptCallStack = currentScriptCallStack(ScriptCallStack::maxCallStackSizeToCapture);
+    // The CPU profiler stack trace does not include call site line numbers.
+    // So we collect the top frame with the currentScriptCallStack to get the
+    // binding call site info.
+    RefPtr<ScriptCallStack> scriptCallStack = currentScriptCallStack(1);

[caseq, 2016/01/27 23:03:56]

nit: put under if ()

[alph, 2016/01/27 23:16:20]

Done.

     if (scriptCallStack)
         scriptCallStack->toTracedValue(value, "stackTrace");
+    v8::Isolate::GetCurrent()->GetCpuProfiler()->CollectSample();
 }
 
 namespace {