Plumb can_use_lcd_text, contents_opaque directly to ContentLayerClient.

cc/layers/content_layer.cc

 // Copyright 2010 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/content_layer.h"
 
 #include "base/auto_reset.h"
 #include "base/metrics/histogram.h"
 #include "base/time/time.h"
 #include "cc/layers/content_layer_client.h"
 #include "cc/resources/bitmap_content_layer_updater.h"
 #include "cc/resources/bitmap_skpicture_content_layer_updater.h"
 #include "cc/resources/layer_painter.h"
 #include "cc/trees/layer_tree_host.h"
 #include "third_party/skia/include/core/SkPictureRecorder.h"
 
 namespace cc {
 
 ContentLayerPainter::ContentLayerPainter(ContentLayerClient* client)
     : client_(client) {}
 
 scoped_ptr<ContentLayerPainter> ContentLayerPainter::Create(
     ContentLayerClient* client) {
   return make_scoped_ptr(new ContentLayerPainter(client));
 }
 
 void ContentLayerPainter::Paint(SkCanvas* canvas,
-                                const gfx::Rect& content_rect) {
+                                const gfx::Rect& content_rect,
+                                bool can_use_lcd_text,
+                                bool contents_opaque) {
   client_->PaintContents(canvas,
                          content_rect,
+                         can_use_lcd_text,
+                         contents_opaque,
                          ContentLayerClient::GRAPHICS_CONTEXT_ENABLED);
 }
 
 scoped_refptr<ContentLayer> ContentLayer::Create(ContentLayerClient* client) {
   return make_scoped_refptr(new ContentLayer(client));
 }
 
 ContentLayer::ContentLayer(ContentLayerClient* client)
     : TiledLayer(),
       client_(client),
-      can_use_lcd_text_last_frame_(can_use_lcd_text()) {
+      can_use_lcd_text_last_frame_(false),
+      first_update_lcd_text_occured_(false) {
 }
 
 ContentLayer::~ContentLayer() {}
 
 void ContentLayer::ClearClient() {
   client_ = nullptr;
   UpdateDrawsContent(HasDrawableContent());
 }
 
 bool ContentLayer::HasDrawableContent() const {
@@ skipping 68 matching lines @@
       layer_tree_host()->GetRendererCapabilities().best_texture_format);
 }
 
 void ContentLayer::SetContentsOpaque(bool opaque) {
   Layer::SetContentsOpaque(opaque);
   if (updater_.get())
     updater_->SetOpaque(opaque);
 }
 
 void ContentLayer::UpdateCanUseLCDText() {
-  if (can_use_lcd_text_last_frame_ == can_use_lcd_text())
-    return;
+  if (first_update_lcd_text_occured_) {
+    if (can_use_lcd_text_last_frame_ == can_use_lcd_text())
+      return;
+    // LCD text can turn off but never on.
+    if (!can_use_lcd_text_last_frame_)
+      return;
+  }
 
   can_use_lcd_text_last_frame_ = can_use_lcd_text();
-  if (client_)
-    client_->DidChangeLayerCanUseLCDText();

[enne (OOO), 2014/11/12 18:51:05]

I don't think this can go.  The reason this was implemented in
WebContentLayerImpl and not inside of this function is because Blink wanted
invalidations and ui::Layer did not.  ui::Layer never wants invalidations when
lcd changes.

[danakj, 2014/11/12 18:52:48]

Ah okay, makes sense now that I saw the ui::Layer differences. Thanks.

+  updater_->SetCanUseLCDText(can_use_lcd_text_last_frame_);
+  first_update_lcd_text_occured_ = true;
+  SetNeedsDisplay();
 }
 
 bool ContentLayer::SupportsLCDText() const {
   return true;
 }
 
 skia::RefPtr<SkPicture> ContentLayer::GetPicture() const {
   if (!DrawsContent())
     return skia::RefPtr<SkPicture>();
 
   int width = bounds().width();
   int height = bounds().height();
 
   SkPictureRecorder recorder;
   SkCanvas* canvas = recorder.beginRecording(width, height, nullptr, 0);
   client_->PaintContents(canvas,
                          gfx::Rect(width, height),
+                         can_use_lcd_text_last_frame_,
+                         contents_opaque(),
                          ContentLayerClient::GRAPHICS_CONTEXT_ENABLED);
   skia::RefPtr<SkPicture> picture = skia::AdoptRef(recorder.endRecording());
   return picture;
 }
 
 void ContentLayer::OnOutputSurfaceCreated() {
   SetTextureFormat(
       layer_tree_host()->GetRendererCapabilities().best_texture_format);
   TiledLayer::OnOutputSurfaceCreated();
 }
 
 }  // namespace cc