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

Always tell blink that it can use LCD text (in future this can stop
being passed at all). And at raster time:

- If LCD text is allowed initialize SkSurfaceProps with the LegacyHost
parameter which will cause skia to pick an LCD text format matching
current behaviour.
- If LCD is not allowed initialize SkSurfaceProps with an "unknown
pixelformat" causing LCD text to not be used.

This also removes the need for SK_SUPPORT_LEGACY_TEXTRENDERMODE from
resource_provider.cc.

R=enne,reveman
BUG=430617

Review URL: https://codereview.chromium.org/684543006

Cr-Commit-Position: refs/heads/master@{#304486}

2 files changed, 5 insertions, 21 deletions

diff --git a/cc/blink/web_content_layer_impl.cc b/cc/blink/web_content_layer_impl.cc
index 6dfdad9..d0a4cca 100644
--- a/cc/blink/web_content_layer_impl.cc
+++ b/cc/blink/web_content_layer_impl.cc
@@ -19,13 +19,12 @@ using cc::PictureLayer;
 namespace cc_blink {
 
 WebContentLayerImpl::WebContentLayerImpl(blink::WebContentLayerClient* client)
-    : client_(client), ignore_lcd_text_change_(false) {
+    : client_(client) {
   if (WebLayerImpl::UsingPictureLayer())
     layer_ = make_scoped_ptr(new WebLayerImpl(PictureLayer::Create(this)));
   else
     layer_ = make_scoped_ptr(new WebLayerImpl(ContentLayer::Create(this)));
   layer_->layer()->SetIsDrawable(true);
-  can_use_lcd_text_ = layer_->layer()->can_use_lcd_text();
 }
 
 WebContentLayerImpl::~WebContentLayerImpl() {
@@ -54,30 +53,16 @@ void WebContentLayerImpl::PaintContents(
   if (!client_)
     return;
 
+  // TODO(danakj): Stop passing this to blink it should always use LCD when it
+  // wants to. crbug.com/430617
+  bool can_use_lcd_text = true;
   client_->paintContents(
-      canvas,
-      clip,
-      can_use_lcd_text_,
+      canvas, clip, can_use_lcd_text,
       graphics_context_status == ContentLayerClient::GRAPHICS_CONTEXT_ENABLED
           ? blink::WebContentLayerClient::GraphicsContextEnabled
           : blink::WebContentLayerClient::GraphicsContextDisabled);
 }
 
-void WebContentLayerImpl::DidChangeLayerCanUseLCDText() {
-  // It is important to make this comparison because the LCD text status
-  // here can get out of sync with that in the layer.
-  if (can_use_lcd_text_ == layer_->layer()->can_use_lcd_text())
-    return;
-
-  // LCD text cannot be enabled once disabled.
-  if (layer_->layer()->can_use_lcd_text() && ignore_lcd_text_change_)
-    return;
-
-  can_use_lcd_text_ = layer_->layer()->can_use_lcd_text();
-  ignore_lcd_text_change_ = true;
-  layer_->invalidate();
-}
-
 bool WebContentLayerImpl::FillsBoundsCompletely() const {
   return false;
 }
diff --git a/cc/blink/web_content_layer_impl.h b/cc/blink/web_content_layer_impl.h
index b9bb871..2966bd4 100644
--- a/cc/blink/web_content_layer_impl.h
+++ b/cc/blink/web_content_layer_impl.h
@@ -40,7 +40,6 @@ class WebContentLayerImpl : public blink::WebContentLayer,
                      const gfx::Rect& clip,
                      ContentLayerClient::GraphicsContextStatus
                          graphics_context_status) override;
-  void DidChangeLayerCanUseLCDText() override;
   bool FillsBoundsCompletely() const override;
 
   scoped_ptr<WebLayerImpl> layer_;