cc: Early out of UpdateTiles for resoureceless draw

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 <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 395 matching lines @@
   }
 
   // Aggressively remove any tilings that are not seen to save memory. Note
   // that this is at the expense of doing cause more frequent re-painting. A
   // better scheme would be to maintain a tighter visible_layer_rect for the
   // finer tilings.
   CleanUpTilingsOnActiveLayer(last_append_quads_tilings_);
 }
 
 bool PictureLayerImpl::UpdateTiles(bool resourceless_software_draw) {
-  if (!resourceless_software_draw) {
-    visible_rect_for_tile_priority_ = visible_layer_rect();
-    screen_space_transform_for_tile_priority_ = ScreenSpaceTransform();
-  }
-
   if (!CanHaveTilings()) {
     ideal_page_scale_ = 0.f;
     ideal_device_scale_ = 0.f;
     ideal_contents_scale_ = 0.f;
     ideal_source_scale_ = 0.f;
     SanityCheckTilingState();
     return false;
   }
 
   // Remove any non-ideal tilings that were not used last time we generated
   // quads to save memory and processing time. Note that pending tree should
   // only have one or two tilings (high and low res), so only clean up the
   // active layer. This cleans it up here in case AppendQuads didn't run.
   // If it did run, this would not remove any additional tilings.
   if (layer_tree_impl()->IsActiveTree())
     CleanUpTilingsOnActiveLayer(last_append_quads_tilings_);
 
+  if (resourceless_software_draw)
+    return false;
+
   UpdateIdealScales();
 
   if (!raster_contents_scale_ || ShouldAdjustRasterScale()) {
     RecalculateRasterScales();
     AddTilingsForRasterScale();
   }
 
   if (layer_tree_impl()->IsActiveTree())
     AddLowResolutionTilingIfNeeded();
 
@@ skipping 39 matching lines @@
   // Pass |occlusion_in_content_space| for |occlusion_in_layer_space| since
   // they are the same space in picture layer, as contents scale is always 1.
   bool updated = tilings_->UpdateTilePriorities(
       viewport_rect_for_tile_priority_in_content_space_, ideal_contents_scale_,
       current_frame_time_in_seconds, occlusion_in_content_space,
       can_require_tiles_for_activation);
   return updated;
 }
 
 void PictureLayerImpl::UpdateViewportRectForTilePriorityInContentSpace() {
-  // If visible_rect_for_tile_priority_ is empty or
-  // viewport_rect_for_tile_priority is set to be different from the device
-  // viewport, try to inverse project the viewport into layer space and use
-  // that. Otherwise just use visible_rect_for_tile_priority_
-  gfx::Rect visible_rect_in_content_space = visible_rect_for_tile_priority_;
+  // If visible_layer_rect() is empty or viewport_rect_for_tile_priority is
+  // set to be different from the device viewport, try to inverse project the
+  // viewport into layer space and use that. Otherwise just use
+  // visible_layer_rect().
+  gfx::Rect visible_rect_in_content_space = visible_layer_rect();
   gfx::Rect viewport_rect_for_tile_priority =
       layer_tree_impl()->ViewportRectForTilePriority();
   if (visible_rect_in_content_space.IsEmpty() ||
       layer_tree_impl()->DeviceViewport() != viewport_rect_for_tile_priority) {
     gfx::Transform view_to_layer(gfx::Transform::kSkipInitialization);
-    if (screen_space_transform_for_tile_priority_.GetInverse(&view_to_layer)) {
+    if (ScreenSpaceTransform().GetInverse(&view_to_layer)) {
       // Transform from view space to content space.
       visible_rect_in_content_space = MathUtil::ProjectEnclosingClippedRect(
           view_to_layer, viewport_rect_for_tile_priority);
 
       // We have to allow for a viewport that is outside of the layer bounds in
       // order to compute tile priorities correctly for offscreen content that
       // is going to make it on screen. However, we also have to limit the
       // viewport since it can be very large due to screen_space_transforms. As
       // a heuristic, we clip to bounds padded by skewport_extrapolation_limit *
       // maximum tiling scale, since this should allow sufficient room for
@@ skipping 737 matching lines @@
 
 bool PictureLayerImpl::IsOnActiveOrPendingTree() const {
   return !layer_tree_impl()->IsRecycleTree();
 }
 
 bool PictureLayerImpl::HasValidTilePriorities() const {
   return IsOnActiveOrPendingTree() && IsDrawnRenderSurfaceLayerListMember();
 }
 
 }  // namespace cc