Optimize PictureLayerTilingSet::visible_rect_history_ type.

Appending entries to visible_rect_history was a hotspot in profiling.
Changing to std::deque, and re-ordering the update code so the deque
only grows to 2 entries rather than 3.

BUG=879668

Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I576ba0ae278a04a0e7336b3b1cd589fadd25b177
Reviewed-on: https://chromium-review.googlesource.com/1200466Reviewed-by: Eric Karl <ericrk@chromium.org>
Commit-Queue: Victor Miura <vmiura@chromium.org>
Cr-Commit-Position: refs/heads/master@{#588238}

cc/tiles/picture_layer_tiling_set.cc

@@ -514,10 +514,10 @@ void PictureLayerTilingSet::UpdatePriorityRects(
   // Finally, update our visible rect history. Note that we use the original
   // visible rect here, since we want as accurate of a history as possible for
   // stable skewports.
+  if (visible_rect_history_.size() == 2)
+    visible_rect_history_.pop_back();
   visible_rect_history_.push_front(FrameVisibleRect(
       visible_rect_in_layer_space_, current_frame_time_in_seconds));
-  if (visible_rect_history_.size() > 2)
-    visible_rect_history_.pop_back();
 }
 
 bool PictureLayerTilingSet::UpdateTilePriorities(

cc/tiles/picture_layer_tiling_set.h

@@ -7,7 +7,7 @@
 
 #include <stddef.h>
 
-#include <list>
+#include <deque>
 #include <set>
 #include <vector>
 
@@ -250,8 +250,8 @@ class CC_EXPORT PictureLayerTilingSet {
   PictureLayerTilingClient* client_;
   const float max_preraster_distance_;
   // State saved for computing velocities based on finite differences.
-  // .front() of the list refers to the most recent FrameVisibleRect.
-  std::list<FrameVisibleRect> visible_rect_history_;
+  // .front() of the deque refers to the most recent FrameVisibleRect.
+  std::deque<FrameVisibleRect> visible_rect_history_;
   StateSinceLastTilePriorityUpdate state_since_last_tile_priority_update_;
 
   scoped_refptr<RasterSource> raster_source_;