Store recording invalidations in DisplayListRecordingSource, save them via Update.

cc/playback/display_list_recording_source.cc

 // Copyright 2014 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/playback/display_list_recording_source.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 
@@ skipping 99 matching lines @@
   invalidation->Union(no_longer_exposed_region);
 }
 
 void DisplayListRecordingSource::FinishDisplayItemListUpdate() {
   DetermineIfSolidColor();
   display_list_->EmitTraceSnapshot();
   if (generate_discardable_images_metadata_)
     display_list_->GenerateDiscardableImagesMetadata();
 }
 
+void DisplayListRecordingSource::SetNeedsDisplayRect(
+    const gfx::Rect& layer_rect) {
+  if (!layer_rect.IsEmpty()) {
+    // Clamp invalidation to the layer bounds.
+    invalidation_.Union(gfx::IntersectRects(layer_rect, gfx::Rect(size_)));
+  }
+}
+
 bool DisplayListRecordingSource::UpdateAndExpandInvalidation(
     ContentLayerClient* painter,
     Region* invalidation,
     const gfx::Size& layer_size,
     const gfx::Rect& visible_layer_rect,
     int frame_number,
     RecordingMode recording_mode) {
   ScopedDisplayListRecordingSourceUpdateTimer timer;
   bool updated = false;
 
   // TODO(chrishtr): delete this conditional once synchronized paint launches.
   if (size_ != layer_size) {
     size_ = layer_size;
     updated = true;
   }
 
+  invalidation_.Swap(invalidation);
+  invalidation_.Clear();
+
   gfx::Rect new_recorded_viewport = painter->PaintableRegion();
   if (new_recorded_viewport != recorded_viewport_) {
     UpdateInvalidationForNewViewport(recorded_viewport_, new_recorded_viewport,
                                      invalidation);
     recorded_viewport_ = new_recorded_viewport;
     updated = true;
   }
 
   // Count the area that is being invalidated.
   Region recorded_invalidation(*invalidation);
   recorded_invalidation.Intersect(recorded_viewport_);
   for (Region::Iterator it(recorded_invalidation); it.has_rect(); it.next())
     timer.AddArea(it.rect().size().GetCheckedArea());
 
   if (!updated && !invalidation->Intersects(recorded_viewport_))
     return false;
 
+  if (invalidation->IsEmpty())
+    return false;
+
   ContentLayerClient::PaintingControlSetting painting_control =
       ContentLayerClient::PAINTING_BEHAVIOR_NORMAL;
 
   switch (recording_mode) {
     case RECORD_NORMALLY:
       // Already setup for normal recording.
       break;
     case RECORD_WITH_PAINTING_DISABLED:
       painting_control = ContentLayerClient::DISPLAY_LIST_PAINTING_DISABLED;
       break;
@@ skipping 77 matching lines @@
 }
 
 void DisplayListRecordingSource::Clear() {
   recorded_viewport_ = gfx::Rect();
   display_list_ = nullptr;
   painter_reported_memory_usage_ = 0;
   is_solid_color_ = false;
 }
 
 }  // namespace cc