Add a flag to disable partial raster in renderer

cc/tiles/picture_layer_tiling.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/tiles/picture_layer_tiling.h"
 
 #include <algorithm>
 #include <cmath>
 #include <limits>
 #include <set>
@@ skipping 123 matching lines @@
     if (find != tiles_.end())
       continue;
 
     Tile::CreateInfo info = CreateInfoForTile(key.index_x, key.index_y);
     if (ShouldCreateTileAt(info)) {
       Tile* tile = CreateTile(info);
 
       // If this is the pending tree, then the active twin tiling may contain
       // the previous content ID of these tiles. In that case, we need only
       // partially raster the tile content.
-      if (tile && invalidation && TilingMatchesTileIndices(active_twin)) {
+      if (client_->EnablePartialRaster() && tile && invalidation &&
+          TilingMatchesTileIndices(active_twin)) {
         if (const Tile* old_tile =
                 active_twin->TileAt(key.index_x, key.index_y)) {
           gfx::Rect tile_rect = tile->content_rect();
           gfx::Rect invalidated;
           for (Region::Iterator iter(*invalidation); iter.has_rect();
                iter.next()) {
             gfx::Rect invalid_content_rect =
                 gfx::ScaleToEnclosingRect(iter.rect(), contents_scale_);
             invalid_content_rect.Intersect(tile_rect);
             invalidated.Union(invalid_content_rect);
@@ skipping 177 matching lines @@
   for (const auto& pair : remove_tiles) {
     const TileMapKey& key = pair.first;
     const gfx::Rect& invalid_content_rect = pair.second;
     // TODO(danakj): This old_tile will not exist if we are committing to a
     // pending tree since there is no tile there to remove, which prevents
     // tiles from knowing the invalidation rect and content id. crbug.com/490847
     ScopedTilePtr old_tile = TakeTileAt(key.index_x, key.index_y);
     if (recreate_tiles && old_tile) {
       Tile::CreateInfo info = CreateInfoForTile(key.index_x, key.index_y);
       if (Tile* tile = CreateTile(info))
         tile->SetInvalidated(invalid_content_rect, old_tile->id());

[vmpstr, 2015/10/06 18:35:48]

You probably need a similar check here. (with test please)

[ericrk, 2015/10/07 17:59:08]

Yup - missed this and had a unit test bug =/... I've updated this as well as the
tests. Thanks!

     }
   }
 }
 
 Tile::CreateInfo PictureLayerTiling::CreateInfoForTile(int i, int j) const {
   gfx::Rect tile_rect = tiling_data_.TileBoundsWithBorder(i, j);
   tile_rect.set_size(tiling_data_.max_texture_size());
   gfx::Rect enclosing_layer_rect =
       gfx::ScaleToEnclosingRect(tile_rect, 1.f / contents_scale_);
   return Tile::CreateInfo(i, j, enclosing_layer_rect, tile_rect,
@@ skipping 652 matching lines @@
 size_t PictureLayerTiling::GPUMemoryUsageInBytes() const {
   size_t amount = 0;
   for (TileMap::const_iterator it = tiles_.begin(); it != tiles_.end(); ++it) {
     const Tile* tile = it->second;
     amount += tile->GPUMemoryUsageInBytes();
   }
   return amount;
 }
 
 }  // namespace cc