cc: add rasterize time to continuous painting graph data in impl-side-painting

cc/paint_time_counter.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 "cc/paint_time_counter.h"
 
 namespace cc {
 
 // static
 scoped_ptr<PaintTimeCounter> PaintTimeCounter::create() {
   return make_scoped_ptr(new PaintTimeCounter());
 }
 
-PaintTimeCounter::PaintTimeCounter() {
+PaintTimeCounter::PaintTimeCounter()
+  : can_save_paint_time_delta(false),
+    can_save_rasterize_time_delta(false) {
 }
 
 base::TimeDelta PaintTimeCounter::GetPaintTimeOfRecentFrame(
     const size_t& n) const {
   DCHECK(n < ring_buffer_.BufferSize());
 
   if (ring_buffer_.IsFilledIndex(n))
-    return ring_buffer_.ReadBuffer(n);
+    return ring_buffer_.ReadBuffer(n).time();
 
   return base::TimeDelta();
 }
 
-void PaintTimeCounter::SavePaintTime(const base::TimeDelta& total_paint_time) {
-  base::TimeDelta paint_time = total_paint_time - last_total_paint_time_;
-
-  if (paint_time.InMillisecondsF() > 0)
-    ring_buffer_.SaveToBuffer(paint_time);
+void PaintTimeCounter::SavePaintTime(const base::TimeDelta& total_paint_time,
+                                     const int& commit_number) {
+  if (can_save_paint_time_delta) {

[egraether, 2013/02/13 20:28:07]

These checks that no entry gets saved, when it's not possible to calculate a
correct delta time. It's not possible to check for num entries of the buffer,
since there are no. I renamed the flags to make this more clear.

+    Entry entry;
+    entry.commit_number = commit_number;
+    entry.paint_time = total_paint_time - last_total_paint_time_;
+    ring_buffer_.SaveToBuffer(entry);
+  }
 
   last_total_paint_time_ = total_paint_time;
+  can_save_paint_time_delta = true;
+}
+
+void PaintTimeCounter::SaveRasterizeTime(
+    const base::TimeDelta& total_rasterize_time,
+    const int& commit_number) {
+  if (can_save_rasterize_time_delta) {
+    Entry entry = ring_buffer_.MutableReadBuffer(ring_buffer_.BufferSize() - 1);
+    DCHECK(commit_number == entry.commit_number);

[egraether, 2013/02/13 20:28:07]

This checks whether the assumption that rasterize time is saved after paint time
holds true. It's also the only place now where Entry.commit_number is used.

+    entry.rasterize_time = total_rasterize_time - last_total_rasterize_time_;
+  }
+
+  last_total_rasterize_time_ = total_rasterize_time;
+  can_save_rasterize_time_delta = true;
 }
 
 void PaintTimeCounter::GetMinAndMaxPaintTime(base::TimeDelta* min,
                                              base::TimeDelta* max) const {
   *min = base::TimeDelta::FromDays(1);
   *max = base::TimeDelta();
 
   for (size_t i = 0; i < ring_buffer_.BufferSize(); i++) {
     if (ring_buffer_.IsFilledIndex(i)) {
-      base::TimeDelta paint_time = ring_buffer_.ReadBuffer(i);
+      base::TimeDelta paint_time = ring_buffer_.ReadBuffer(i).time();
 
       if (paint_time < *min)
         *min = paint_time;
       if (paint_time > *max)
         *max = paint_time;
     }
   }
 
   if (*min > *max)
     *min = *max;
 }
 
+void PaintTimeCounter::ClearHistory() {
+  ring_buffer_.Clear();
+  can_save_paint_time_delta = false;
+  can_save_rasterize_time_delta = false;
+}
+
 }  // namespace cc