[cc] Use base::TimeTicks in RenderStats

cc/picture_pile_impl.cc

 // Copyright 2012 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 "base/debug/trace_event.h"
 #include "cc/picture_pile_impl.h"
 #include "cc/rendering_stats.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkSize.h"
 #include "ui/gfx/rect_conversions.h"
@@ skipping 70 matching lines @@
 
     // Don't allow pictures underneath to draw where this picture did.
     canvas->clipRect(gfx::RectToSkRect(content_clip), SkRegion::kDifference_Op);
     unclipped.Subtract(content_clip);
 
     stats->totalPixelsRasterized +=
         content_clip.width() * content_clip.height();
   }
   canvas->restore();
 
-  stats->totalRasterizeTimeInSeconds += (base::TimeTicks::Now() -
-                                         rasterizeBeginTime).InSecondsF();
+  stats->totalRasterizeTime += base::TimeTicks::Now() - rasterizeBeginTime;
 }
 
 void PicturePileImpl::GatherPixelRefs(
     const gfx::Rect& rect, std::list<skia::LazyPixelRef*>& pixel_refs) {
   std::list<skia::LazyPixelRef*> result;
   for (PicturePile::Pile::const_iterator i = pile_.begin();
       i != pile_.end(); ++i) {
     (*i)->GatherPixelRefs(rect, result);
     pixel_refs.splice(pixel_refs.end(), result);
   }
@@ skipping 18 matching lines @@
       SkPicture::kUsePathBoundsForClip_RecordingFlag);
 
   RenderingStats stats;
   Raster(canvas, layer_rect, 1.0, &stats);
   picture->endRecording();
 
   return picture;
 }
 
 }  // namespace cc