cc: Save correct frame begin time to FrameRateCounter

cc/layer_tree_host_impl.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/layer_tree_host_impl.h"
 
 #include <algorithm>
 
 #include "base/basictypes.h"
 #include "base/debug/trace_event.h"
@@ skipping 776 matching lines @@
     }
 
     if (!rootScrollLayer())
       return metadata;
 
     metadata.root_scroll_offset = rootScrollLayer()->scroll_offset() + rootScrollLayer()->scroll_delta();
 
     return metadata;
 }
 
-void LayerTreeHostImpl::drawLayers(FrameData& frame)
+void LayerTreeHostImpl::drawLayers(FrameData& frame, base::TimeTicks frameBeginTime)
 {
     TRACE_EVENT0("cc", "LayerTreeHostImpl::drawLayers");
     DCHECK(canDraw());
     DCHECK(!frame.renderPasses.empty());
 
-    // FIXME: use the frame begin time from the overall compositor scheduler.
-    // This value is currently inaccessible because it is up in Chromium's
-    // RenderWidget.
-    m_fpsCounter->saveTimeStamp(base::TimeTicks::Now());
+    m_fpsCounter->saveTimeStamp(frameBeginTime);
 
     if (m_tileManager) {
         m_memoryHistory->SaveEntry(
             m_tileManager->memory_stats_from_last_assign());
     }
 
     if (m_debugState.showHudRects())
         m_debugRectHistory->saveDebugRectsForCurrentFrame(rootLayer(), *frame.renderSurfaceLayerList, frame.occludingScreenSpaceRects, frame.nonOccludingScreenSpaceRects, m_debugState);
 
     if (m_debugState.traceAllRenderedFrames) {
@@ skipping 913 matching lines @@
         m_tileManager->SetRecordRenderingStats(m_debugState.recordRenderingStats());
 }
 
 void LayerTreeHostImpl::savePaintTime(const base::TimeDelta& totalPaintTime, int commitNumber)
 {
     DCHECK(m_debugState.continuousPainting);
     m_paintTimeCounter->SavePaintTime(totalPaintTime, commitNumber);
 }
 
 }  // namespace cc