cc: Toggle LCD text at raster time instead of record time.

cc/layers/picture_layer.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/layers/picture_layer.h"
 
 #include "base/auto_reset.h"
 #include "cc/layers/content_layer_client.h"
 #include "cc/layers/picture_layer_impl.h"
 #include "cc/resources/picture_pile.h"
 #include "cc/trees/layer_tree_impl.h"
 #include "third_party/skia/include/core/SkPictureRecorder.h"
 #include "ui/gfx/geometry/rect_conversions.h"
 
 namespace cc {
 
 scoped_refptr<PictureLayer> PictureLayer::Create(ContentLayerClient* client) {
   return make_scoped_refptr(new PictureLayer(client));
 }
 
 PictureLayer::PictureLayer(ContentLayerClient* client)
     : client_(client),
       recording_source_(new PicturePile),
       instrumentation_object_tracker_(id()),
       update_source_frame_number_(-1),
-      can_use_lcd_text_last_frame_(can_use_lcd_text()),
+      can_use_lcd_text_for_update_(true),
       is_mask_(false) {
 }
 
 PictureLayer::PictureLayer(ContentLayerClient* client,
                            scoped_ptr<RecordingSource> source)
     : PictureLayer(client) {
   recording_source_ = source.Pass();
 }
 
 PictureLayer::~PictureLayer() {
@@ skipping 57 matching lines @@
         gfx::IntersectRects(layer_rect, gfx::Rect(bounds())));
   }
   Layer::SetNeedsDisplayRect(layer_rect);
 }
 
 bool PictureLayer::Update(ResourceUpdateQueue* queue,
                           const OcclusionTracker<Layer>* occlusion) {
   update_source_frame_number_ = layer_tree_host()->source_frame_number();
   bool updated = Layer::Update(queue, occlusion);
 
-  {
-    base::AutoReset<bool> ignore_set_needs_commit(&ignore_set_needs_commit_,
-                                                  true);
-    UpdateCanUseLCDText();
-  }
+  bool can_use_lcd_text_changed = UpdateCanUseLCDText();
 
   gfx::Rect visible_layer_rect = gfx::ScaleToEnclosingRect(
       visible_content_rect(), 1.f / contents_scale_x());
   gfx::Size layer_size = paint_properties().bounds;
 
   if (last_updated_visible_content_rect_ == visible_content_rect() &&
-      recording_source_->GetSize() == layer_size &&
+      recording_source_->GetSize() == layer_size && !can_use_lcd_text_changed &&
       pending_invalidation_.IsEmpty()) {
     // Only early out if the visible content rect of this layer hasn't changed.
     return updated;
   }
 
   TRACE_EVENT1("cc", "PictureLayer::Update",
                "source_frame_number",
                layer_tree_host()->source_frame_number());
   devtools_instrumentation::ScopedLayerTreeTask update_layer(
       devtools_instrumentation::kUpdateLayer, id(), layer_tree_host()->id());
 
   // Calling paint in WebKit can sometimes cause invalidations, so save
   // off the invalidation prior to calling update.
   pending_invalidation_.Swap(&recording_invalidation_);
   pending_invalidation_.Clear();
 
   if (layer_tree_host()->settings().record_full_layer) {
     // Workaround for http://crbug.com/235910 - to retain backwards compat
     // the full page content must always be provided in the picture layer.
     visible_layer_rect = gfx::Rect(layer_size);
   }
 
   // UpdateAndExpandInvalidation will give us an invalidation that covers
   // anything not explicitly recorded in this frame. We give this region
   // to the impl side so that it drops tiles that may not have a recording
   // for them.
   DCHECK(client_);
   updated |= recording_source_->UpdateAndExpandInvalidation(
-      client_, &recording_invalidation_, layer_size, visible_layer_rect,
-      update_source_frame_number_, Picture::RECORD_NORMALLY);
+      client_, &recording_invalidation_, can_use_lcd_text_for_update_,
+      layer_size, visible_layer_rect, update_source_frame_number_,
+      Picture::RECORD_NORMALLY);
   last_updated_visible_content_rect_ = visible_content_rect();
 
   if (updated) {
     SetNeedsPushProperties();
   } else {
     // If this invalidation did not affect the recording source, then it can be
     // cleared as an optimization.
     recording_invalidation_.Clear();
   }
 
   return updated;
 }
 
 void PictureLayer::SetIsMask(bool is_mask) {
   is_mask_ = is_mask;
 }
 
 bool PictureLayer::SupportsLCDText() const {
   return true;
 }
 
-void PictureLayer::UpdateCanUseLCDText() {
-  if (can_use_lcd_text_last_frame_ == can_use_lcd_text())
-    return;
+bool PictureLayer::UpdateCanUseLCDText() {
+  if (!can_use_lcd_text_for_update_)
+    return false;  // Don't allow the LCD text state to change once disabled.
+  if (can_use_lcd_text_for_update_ == can_use_lcd_text())
+    return false;
 
-  can_use_lcd_text_last_frame_ = can_use_lcd_text();
-  if (client_)
-    client_->DidChangeLayerCanUseLCDText();
+  can_use_lcd_text_for_update_ = can_use_lcd_text();
+  return true;
 }
 
 skia::RefPtr<SkPicture> PictureLayer::GetPicture() const {
   // We could either flatten the RecordingSource into a single SkPicture,
   // or paint a fresh one depending on what we intend to do with the
   // picture. For now we just paint a fresh one to get consistent results.
   if (!DrawsContent())
     return skia::RefPtr<SkPicture>();
 
   int width = bounds().width();
@@ skipping 19 matching lines @@
 
 bool PictureLayer::HasDrawableContent() const {
   return client_ && Layer::HasDrawableContent();
 }
 
 void PictureLayer::RunMicroBenchmark(MicroBenchmark* benchmark) {
   benchmark->RunOnLayer(this);
 }
 
 }  // namespace cc