Retry tree activation if raster tasks finish during first half of vsync interval

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 <string>
 
 #include "base/bind.h"
@@ skipping 441 matching lines @@
 }
 
 void TileManager::DidFinishDispatchingWorkerPoolCompletionCallbacks() {
   // If a flush is needed, do it now before starting to dispatch more tasks.
   if (has_performed_uploads_since_last_flush_) {
     resource_pool_->resource_provider()->ShallowFlushIfSupported();
     has_performed_uploads_since_last_flush_ = false;
   }
 
   DispatchMoreTasks();
+  if (!pending_tasks_)
+    client_->DidFinishTileRasterTasks();
 }
 
 void TileManager::AssignGpuMemoryToTiles() {
   TRACE_EVENT0("cc", "TileManager::AssignGpuMemoryToTiles");
   size_t unreleasable_bytes = 0;
 
   // Now give memory out to the tiles until we're out, and build
   // the needs-to-be-rasterized queue.
   tiles_that_need_to_be_rasterized_.clear();
 
@@ skipping 504 matching lines @@
     skia::LazyPixelRef* pixel_ref,
     RenderingStatsInstrumentation* stats_instrumentation) {
   TRACE_EVENT0("cc", "TileManager::RunImageDecodeTask");
   base::TimeTicks start_time = stats_instrumentation->StartRecording();
   pixel_ref->Decode();
   base::TimeDelta duration = stats_instrumentation->EndRecording(start_time);
   stats_instrumentation->AddDeferredImageDecode(duration);
 }
 
 }  // namespace cc