Update from https://crrev.com/307664

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index 6ec1f0a1b616f9694a366a247f4f56838291c09e..54cfac88b32ec722abac90809ad0c5c9486e7731 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -39,13 +39,6 @@ const float kMaxScaleRatioDuringPinch = 2.0f;
 // 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.
@@ -630,12 +623,8 @@ scoped_refptr<Tile> PictureLayerImpl::CreateTile(PictureLayerTiling* tiling,
 
   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;
 
@@ -684,13 +673,9 @@ size_t PictureLayerImpl::GetMaxTilesForInterestArea() const {
 }
 
 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 {