cc: Add support for partial swaps when using impl-side painting.

cc/resources/tile_manager.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/resources/tile_manager.h"
 
 #include <algorithm>
 #include <limits>
 #include <string>
 
@@ skipping 444 matching lines @@
       rendering_stats_instrumentation_(rendering_stats_instrumentation),
       did_initialize_visible_tile_(false),
       did_check_for_completed_tasks_since_last_schedule_tasks_(true),
       use_rasterize_on_demand_(use_rasterize_on_demand) {
   RasterWorkerPool* raster_worker_pools[NUM_RASTER_WORKER_POOL_TYPES] = {
       raster_worker_pool_.get(),        // RASTER_WORKER_POOL_TYPE_DEFAULT
       direct_raster_worker_pool_.get()  // RASTER_WORKER_POOL_TYPE_DIRECT
   };
   raster_worker_pool_delegate_ = RasterWorkerPoolDelegate::Create(
       this, raster_worker_pools, arraysize(raster_worker_pools));
+  damage_rect_ = gfx::Rect(0, 0, 0, 0);
 }
 
 TileManager::~TileManager() {
   // Reset global state and manage. This should cause
   // our memory usage to drop to zero.
   global_state_ = GlobalStateThatImpactsTilePriority();
 
   CleanUpReleasedTiles();
   DCHECK_EQ(0u, tiles_.size());
 
@@ skipping 15 matching lines @@
     (*it)->DidUnregisterLayer();
   }
   layers_.clear();
 }
 
 void TileManager::Release(Tile* tile) {
   prioritized_tiles_dirty_ = true;
   released_tiles_.push_back(tile);
 }
 
+void TileManager::ResetDamagedRect() { damage_rect_ = gfx::Rect(0, 0, 0, 0); }
+
+gfx::Rect TileManager::GetDamagedRect() { return damage_rect_; }
+
 void TileManager::DidChangeTilePriority(Tile* tile) {
   prioritized_tiles_dirty_ = true;
 }
 
 bool TileManager::ShouldForceTasksRequiredForActivationToComplete() const {
   return global_state_.tree_priority != SMOOTHNESS_TAKES_PRIORITY;
 }
 
 void TileManager::CleanUpReleasedTiles() {
   for (std::vector<Tile*>::iterator it = released_tiles_.begin();
@@ skipping 715 matching lines @@
   DCHECK(tile_version.raster_task_);
   orphan_raster_tasks_.push_back(tile_version.raster_task_);
   tile_version.raster_task_ = NULL;
 
   if (was_canceled) {
     ++update_visible_tiles_stats_.canceled_count;
     resource_pool_->ReleaseResource(resource.Pass());
     return;
   }
 
+  // Union damage rect with current tile's content rect.
+  damage_rect_ = gfx::UnionRects(damage_rect_, tile->content_rect());

[danakj, 2014/04/01 14:22:51]

What space is the damage_rect_ in? If it's in screen space, you'd have to
transform the tile's rect here.

Atm it will be a combination of all possible layers' content spaces, which won't
work when layers have transforms etc.

+
   ++update_visible_tiles_stats_.completed_count;
 
   tile_version.set_has_text(analysis.has_text);
   if (analysis.is_solid_color) {
     tile_version.set_solid_color(analysis.solid_color);
     resource_pool_->ReleaseResource(resource.Pass());
   } else {
     tile_version.set_use_resource();
     tile_version.resource_ = resource.Pass();
 
@@ skipping 85 matching lines @@
     }
   }
 }
 
 TileManager::PairedPictureLayer::PairedPictureLayer()
     : active_layer(NULL), pending_layer(NULL) {}
 
 TileManager::PairedPictureLayer::~PairedPictureLayer() {}
 
 }  // namespace cc