From f97824d368cda4037a7878a6c00821e85ab3fa5b Mon Sep 17 00:00:00 2001
From: Chinmay Garde <chinmaygarde@google.com>
Date: Tue, 1 Dec 2015 15:51:05 -0800
Subject: [PATCH] Add a counter to trace VSync events from the platform

---
 sky/services/vsync/ios/vsync_provider_impl.mm | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sky/services/vsync/ios/vsync_provider_impl.mm b/sky/services/vsync/ios/vsync_provider_impl.mm
index b4787615673..032c67b5b20 100644
--- a/sky/services/vsync/ios/vsync_provider_impl.mm
+++ b/sky/services/vsync/ios/vsync_provider_impl.mm
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "sky/services/vsync/ios/vsync_provider_impl.h"
+#include "base/trace_event/trace_event.h"
 
 #include <Foundation/Foundation.h>
 #include <QuartzCore/CADisplayLink.h>
@@ -25,6 +26,7 @@ static inline uint64_t CurrentTimeMicrosSeconds() {
 @implementation VSyncClient {
   CADisplayLink* _displayLink;
   ::vsync::VSyncProvider::AwaitVSyncCallback _pendingCallback;
+  BOOL _traceLevel;
 }
 
 - (instancetype)init {
@@ -48,6 +50,7 @@ static inline uint64_t CurrentTimeMicrosSeconds() {
 }
 
 - (void)onDisplayLink:(CADisplayLink*)link {
+  TRACE_COUNTER1("vsync", "PlatformVSync", _traceLevel = !_traceLevel);
   _displayLink.paused = YES;
   _pendingCallback.Run(CurrentTimeMicrosSeconds());
 }