cc: Add UMA stats for record and raster time.

cc/resources/display_list_recording_source.cc

Index: cc/resources/display_list_recording_source.cc
diff --git a/cc/resources/display_list_recording_source.cc b/cc/resources/display_list_recording_source.cc
index 3a47c9067ca4dc7e0634aca8269100887a91a304..161829b17da398428fccbd01f6fc10251612d08a 100644
--- a/cc/resources/display_list_recording_source.cc
+++ b/cc/resources/display_list_recording_source.cc
@@ -6,6 +6,7 @@
 
 #include <algorithm>
 
+#include "cc/base/histogram_macros.h"
 #include "cc/base/region.h"
 #include "cc/layers/content_layer_client.h"
 #include "cc/resources/display_item_list.h"
@@ -22,6 +23,11 @@ const int kPixelDistanceToRecord = 8000;
 // operations.
 const int kOpCountThatIsOkToAnalyze = 10;
 
+DEFINE_SCOPED_UMA_HISTOGRAM_AREA_TIMER(
+    ScopedDisplayListRecordingSourceUpdateTimer,
+    "Renderer4.DisplayListRecordingSourceUpdateUs",
+    "Renderer4.DisplayListRecordingSourceUpdatePixelsPerMs");
+
 }  // namespace
 
 namespace cc {
@@ -49,6 +55,7 @@ bool DisplayListRecordingSource::UpdateAndExpandInvalidation(
     const gfx::Rect& visible_layer_rect,
     int frame_number,
     RecordingMode recording_mode) {
+  ScopedDisplayListRecordingSourceUpdateTimer timer;
   bool updated = false;
 
   if (size_ != layer_size) {
@@ -120,6 +127,8 @@ bool DisplayListRecordingSource::UpdateAndExpandInvalidation(
   if (gather_pixel_refs_)
     display_list_->GatherPixelRefs(grid_cell_size_);
 
+  timer.SetArea(recorded_viewport_.size().GetArea());

[chrishtr, 2015/04/10 17:41:39]

What if you just set the area to the invalidation rects, not the
recorded_viewport_?

[jbroman, 2015/04/13 19:34:00]

Changed as discussed in meeting on Friday.

+
   return true;
 }