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

cc/trees/layer_tree_host_impl.cc

 // Copyright 2011 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/trees/layer_tree_host_impl.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/basictypes.h"
@@ skipping 1085 matching lines @@
   frame->render_passes.clear();
   frame->render_passes_by_id.clear();
   frame->will_draw_layers.clear();
   frame->contains_incomplete_tile = false;
   frame->has_no_damage = false;
 
   gfx::Rect device_viewport_damage_rect(damage_rect);
   if (active_tree_->root_layer()) {
     device_viewport_damage_rect.Union(viewport_damage_rect_);
     viewport_damage_rect_ = gfx::Rect();
-
     active_tree_->root_layer()->render_surface()->damage_tracker()->
         AddDamageNextUpdate(device_viewport_damage_rect);
   }
 
   DrawSwapReadbackResult::DrawResult draw_result = CalculateRenderPasses(frame);
   if (draw_result != DrawSwapReadbackResult::DRAW_SUCCESS) {
     DCHECK(!output_surface_->capabilities()
                .draw_and_swap_full_viewport_every_frame);
     return draw_result;
   }
@@ skipping 70 matching lines @@
 }
 
 void LayerTreeHostImpl::DidModifyTilePriorities() {
   DCHECK(settings_.impl_side_painting);
   // Mark priorities as dirty and schedule a ManageTiles().
   tile_priorities_dirty_ = true;
   client_->SetNeedsManageTilesOnImplThread();
 }
 
 void LayerTreeHostImpl::DidInitializeVisibleTile() {
-  // TODO(reveman): Determine tiles that changed and only damage
-  // what's necessary.
-  SetFullRootLayerDamage();
+  std::map<int, gfx::Rect> map = tile_manager_->GetTileRectLayerMap();
+  for (std::map<int, gfx::Rect>::iterator it = map.begin(); it != map.end();
+       ++it) {
+    if (active_tree_)
+      active_tree_->FindActiveTreeLayerById(it->first)
+          ->SetInitializedTileRect(it->second);
+  }
+  tile_manager_->ResetTileRectLayerMap();
+
   if (client_ && !client_->IsInsideDraw())
     client_->DidInitializeVisibleTileOnImplThread();
 }
 
 void LayerTreeHostImpl::NotifyReadyToActivate() {
   client_->NotifyReadyToActivate();
 }
 
 void LayerTreeHostImpl::SetMemoryPolicy(const ManagedMemoryPolicy& policy) {
   SetManagedMemoryPolicy(policy, zero_budget_);
@@ skipping 1820 matching lines @@
   swap_promise_monitor_.erase(monitor);
 }
 
 void LayerTreeHostImpl::NotifySwapPromiseMonitorsOfSetNeedsRedraw() {
   std::set<SwapPromiseMonitor*>::iterator it = swap_promise_monitor_.begin();
   for (; it != swap_promise_monitor_.end(); it++)
     (*it)->OnSetNeedsRedrawOnImpl();
 }
 
 }  // namespace cc