Update from https://crrev.com/315085

cc/debug/devtools_instrumentation.h

Index: cc/debug/devtools_instrumentation.h
diff --git a/cc/debug/devtools_instrumentation.h b/cc/debug/devtools_instrumentation.h
index cfe3e5a2f004e39895a85cd3e0d9da79736ec38f..73788a528af41faeaa85123c81eb51117d46032a 100644
--- a/cc/debug/devtools_instrumentation.h
+++ b/cc/debug/devtools_instrumentation.h
@@ -6,6 +6,7 @@
 #define CC_DEBUG_DEVTOOLS_INSTRUMENTATION_H_
 
 #include "base/trace_event/trace_event.h"
+#include "base/trace_event/trace_event_argument.h"
 
 namespace cc {
 namespace devtools_instrumentation {
@@ -14,6 +15,7 @@ namespace internal {
 const char kCategory[] = TRACE_DISABLED_BY_DEFAULT("devtools.timeline");
 const char kCategoryFrame[] =
     TRACE_DISABLED_BY_DEFAULT("devtools.timeline.frame");
+const char kData[] = "data";
 const char kFrameId[] = "frameId";
 const char kLayerId[] = "layerId";
 const char kLayerTreeId[] = "layerTreeId";
@@ -23,7 +25,9 @@ const char kImageDecodeTask[] = "ImageDecodeTask";
 const char kBeginFrame[] = "BeginFrame";
 const char kActivateLayerTree[] = "ActivateLayerTree";
 const char kRequestMainThreadFrame[] = "RequestMainThreadFrame";
+const char kBeginMainThreadFrame[] = "BeginMainThreadFrame";
 const char kDrawFrame[] = "DrawFrame";
+const char kCompositeLayers[] = "CompositeLayers";
 }  // namespace internal
 
 const char kPaintSetup[] = "PaintSetup";
@@ -77,6 +81,20 @@ class ScopedLayerTreeTask {
   DISALLOW_COPY_AND_ASSIGN(ScopedLayerTreeTask);
 };
 
+struct ScopedCommitTrace {
+ public:
+  explicit ScopedCommitTrace(int layer_tree_host_id) {
+    TRACE_EVENT_BEGIN1(internal::kCategory, internal::kCompositeLayers,
+                       internal::kLayerTreeId, layer_tree_host_id);
+  }
+  ~ScopedCommitTrace() {
+    TRACE_EVENT_END0(internal::kCategory, internal::kCompositeLayers);
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ScopedCommitTrace);
+};
+
 struct ScopedLayerObjectTracker
     : public base::debug::TraceScopedTrackableObject<int> {
   explicit ScopedLayerObjectTracker(int layer_id)
@@ -124,6 +142,21 @@ inline void DidRequestMainThreadFrame(int layer_tree_host_id) {
                        layer_tree_host_id);
 }
 
+inline scoped_refptr<base::debug::ConvertableToTraceFormat>
+BeginMainThreadFrameData(int frame_id) {
+  scoped_refptr<base::debug::TracedValue> value =
+      new base::debug::TracedValue();
+  value->SetInteger("frameId", frame_id);
+  return value;
+}
+
+inline void WillBeginMainThreadFrame(int layer_tree_host_id, int frame_id) {
+  TRACE_EVENT_INSTANT2(
+      internal::kCategoryFrame, internal::kBeginMainThreadFrame,
+      TRACE_EVENT_SCOPE_THREAD, internal::kLayerTreeId, layer_tree_host_id,
+      internal::kData, BeginMainThreadFrameData(frame_id));
+}
+
 }  // namespace devtools_instrumentation
 }  // namespace cc