Update from https://crrev.com/307664

cc/layers/picture_layer_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 "cc/layers/picture_layer_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <set>
 
@@ skipping 21 matching lines @@
 
 namespace {
 // This must be > 1 as we multiply or divide by this to find a new raster
 // scale during pinch.
 const float kMaxScaleRatioDuringPinch = 2.0f;
 
 // When creating a new tiling during pinch, snap to an existing
 // tiling's scale if the desired scale is within this ratio.
 const float kSnapToExistingTilingRatio = 1.2f;
 
-// Estimate skewport 60 frames ahead for pre-rasterization on the CPU.
-const float kCpuSkewportTargetTimeInFrames = 60.0f;
-
-// Don't pre-rasterize on the GPU (except for kBackflingGuardDistancePixels in
-// TileManager::BinFromTilePriority).
-const float kGpuSkewportTargetTimeInFrames = 0.0f;
-
 // Even for really wide viewports, at some point GPU raster should use
 // less than 4 tiles to fill the viewport. This is set to 256 as a
 // sane minimum for now, but we might want to tune this for low-end.
 const int kMinHeightForGpuRasteredTile = 256;
 
 // When making odd-sized tiles, round them up to increase the chances
 // of using the same tile size.
 const int kTileRoundUp = 64;
 
 }  // namespace
@@ skipping 564 matching lines @@
 }
 
 scoped_refptr<Tile> PictureLayerImpl::CreateTile(PictureLayerTiling* tiling,
                                                const gfx::Rect& content_rect) {
   DCHECK(!raster_source_->IsSolidColor());
   if (!raster_source_->CoversRect(content_rect, tiling->contents_scale()))
     return scoped_refptr<Tile>();
 
   int flags = 0;
 
-  // TODO(vmpstr): Revisit this. For now, enabling analysis means that we get as
-  // much savings on memory as we can. However, for some cases like ganesh or
-  // small layers, the amount of time we spend analyzing might not justify
-  // memory savings that we can get. Note that we don't handle solid color
-  // masks, so we shouldn't bother analyzing those.
-  // Bugs: crbug.com/397198, crbug.com/396908
+  // We don't handle solid color masks, so we shouldn't bother analyzing those.
+  // Otherwise, always analyze to maximize memory savings.
   if (!is_mask_)
     flags = Tile::USE_PICTURE_ANALYSIS;
 
   return layer_tree_impl()->tile_manager()->CreateTile(
       raster_source_.get(), content_rect.size(), content_rect,
       tiling->contents_scale(), id(), layer_tree_impl()->source_frame_number(),
       flags);
 }
 
 const Region* PictureLayerImpl::GetPendingInvalidation() {
@@ skipping 28 matching lines @@
   if (!HasValidTilePriorities())
     return TilePriority::EVENTUALLY;
   return TilePriority::NOW;
 }
 
 size_t PictureLayerImpl::GetMaxTilesForInterestArea() const {
   return layer_tree_impl()->settings().max_tiles_for_interest_area;
 }
 
 float PictureLayerImpl::GetSkewportTargetTimeInSeconds() const {
-  float skewport_target_time_in_frames =
-      layer_tree_impl()->use_gpu_rasterization()
-          ? kGpuSkewportTargetTimeInFrames
-          : kCpuSkewportTargetTimeInFrames;
-  return skewport_target_time_in_frames *
-         layer_tree_impl()->begin_impl_frame_interval().InSecondsF() *
-         layer_tree_impl()->settings().skewport_target_time_multiplier;
+  return layer_tree_impl()->use_gpu_rasterization()
+             ? 0.f
+             : layer_tree_impl()->settings().skewport_target_time_in_seconds;
 }
 
 int PictureLayerImpl::GetSkewportExtrapolationLimitInContentPixels() const {
   return layer_tree_impl()
       ->settings()
       .skewport_extrapolation_limit_in_content_pixels;
 }
 
 bool PictureLayerImpl::RequiresHighResToDraw() const {
   return layer_tree_impl()->RequiresHighResToDraw();
@@ skipping 666 matching lines @@
 
 bool PictureLayerImpl::AllTilesRequiredForDrawAreReadyToDraw() const {
   if (!layer_tree_impl()->IsActiveTree())
     return true;
 
   return AllTilesRequiredAreReadyToDraw(
       &PictureLayerTiling::IsTileRequiredForDrawIfVisible);
 }
 
 }  // namespace cc