Remove unused methods in RenderingStatsInstrumentation.

Remove unused methods:
- RenderingStatsInstrumentation::StartRecording
- RenderingStatsInstrumentation::EndRecording

Initializing ThreadTicks in the constructor of
RenderingStatsInstrumentation caused a regression of page load time.
Since StartRecording and EndRecording are not used, this CL removes
these methods + the initialization of ThreadTicks in the constructor.

BUG=543660
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1410713003

Cr-Commit-Position: refs/heads/master@{#354879}

2 files changed, 0 insertions, 24 deletions

diff --git a/cc/debug/rendering_stats_instrumentation.cc b/cc/debug/rendering_stats_instrumentation.cc
index d80d912..94768c6 100644
--- a/cc/debug/rendering_stats_instrumentation.cc
+++ b/cc/debug/rendering_stats_instrumentation.cc
@@ -14,8 +14,6 @@ scoped_ptr<RenderingStatsInstrumentation>
 
 RenderingStatsInstrumentation::RenderingStatsInstrumentation()
     : record_rendering_stats_(false) {
-  if (base::ThreadTicks::IsSupported())
-    base::ThreadTicks::WaitUntilInitialized();
 }
 
 RenderingStatsInstrumentation::~RenderingStatsInstrumentation() {}
@@ -39,25 +37,6 @@ void RenderingStatsInstrumentation::AccumulateAndClearImplThreadStats() {
   impl_thread_rendering_stats_ = RenderingStats();
 }
 
-base::TimeDelta RenderingStatsInstrumentation::StartRecording() const {
-  if (record_rendering_stats_) {
-    if (base::ThreadTicks::IsSupported())
-      return base::ThreadTicks::Now() - base::ThreadTicks();
-    return base::TimeTicks::Now() - base::TimeTicks();
-  }
-  return base::TimeDelta();
-}
-
-base::TimeDelta RenderingStatsInstrumentation::EndRecording(
-    base::TimeDelta start_time) const {
-  if (start_time != base::TimeDelta()) {
-    if (base::ThreadTicks::IsSupported())
-      return (base::ThreadTicks::Now() - base::ThreadTicks()) - start_time;
-    return (base::TimeTicks::Now() - base::TimeTicks()) - start_time;
-  }
-  return base::TimeDelta();
-}
-
 void RenderingStatsInstrumentation::IncrementFrameCount(int64 count) {
   if (!record_rendering_stats_)
     return;
diff --git a/cc/debug/rendering_stats_instrumentation.h b/cc/debug/rendering_stats_instrumentation.h
index 92351e6..834e10c 100644
--- a/cc/debug/rendering_stats_instrumentation.h
+++ b/cc/debug/rendering_stats_instrumentation.h
@@ -37,9 +37,6 @@ class CC_EXPORT RenderingStatsInstrumentation {
       record_rendering_stats_ = record_rendering_stats;
   }
 
-  base::TimeDelta StartRecording() const;
-  base::TimeDelta EndRecording(base::TimeDelta start_time) const;
-
   void IncrementFrameCount(int64 count);
   void AddVisibleContentArea(int64 area);
   void AddApproximatedVisibleContentArea(int64 area);