Allow background tab titles to use LCD AA.

cc/playback/compositing_display_item.cc

 // Copyright 2015 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/compositing_display_item.h"
 
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "cc/proto/display_item.pb.h"
 #include "cc/proto/gfx_conversions.h"
 #include "cc/proto/skia_conversions.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkData.h"
 #include "third_party/skia/include/core/SkFlattenable.h"
 #include "third_party/skia/include/core/SkFlattenableSerialization.h"
 #include "third_party/skia/include/core/SkPaint.h"
 #include "third_party/skia/include/core/SkXfermode.h"
 #include "ui/gfx/skia_util.h"
 
 namespace cc {
 
-CompositingDisplayItem::CompositingDisplayItem(uint8_t alpha,
-                                               SkXfermode::Mode xfermode,
-                                               SkRect* bounds,
-                                               skia::RefPtr<SkColorFilter> cf) {
-  SetNew(alpha, xfermode, bounds, std::move(cf));
+CompositingDisplayItem::CompositingDisplayItem(
+    uint8_t alpha,
+    SkXfermode::Mode xfermode,
+    SkRect* bounds,
+    skia::RefPtr<SkColorFilter> cf,
+    bool lcd_text_requires_opaque_layer) {
+  SetNew(alpha, xfermode, bounds, std::move(cf),
+         lcd_text_requires_opaque_layer);
 }
 
 CompositingDisplayItem::CompositingDisplayItem(
     const proto::DisplayItem& proto) {
   DCHECK_EQ(proto::DisplayItem::Type_Compositing, proto.type());
 
   const proto::CompositingDisplayItem& details = proto.compositing_item();
   uint8_t alpha = static_cast<uint8_t>(details.alpha());
   SkXfermode::Mode xfermode = SkXfermodeModeFromProto(details.mode());
   scoped_ptr<SkRect> bounds;
   if (details.has_bounds()) {
     bounds.reset(
         new SkRect(gfx::RectFToSkRect(ProtoToRectF(details.bounds()))));
   }
 
   skia::RefPtr<SkColorFilter> filter;
   if (details.has_color_filter()) {
     SkFlattenable* flattenable = SkValidatingDeserializeFlattenable(
         details.color_filter().c_str(), details.color_filter().size(),
         SkColorFilter::GetFlattenableType());
     filter = skia::AdoptRef(static_cast<SkColorFilter*>(flattenable));
   }
 
-  SetNew(alpha, xfermode, bounds.get(), std::move(filter));
+  bool lcd_text_requires_opaque_layer =
+      details.lcd_text_requires_opaque_layer();
+
+  SetNew(alpha, xfermode, bounds.get(), std::move(filter),
+         lcd_text_requires_opaque_layer);
 }
 
 CompositingDisplayItem::~CompositingDisplayItem() {
 }
 
 void CompositingDisplayItem::SetNew(uint8_t alpha,
                                     SkXfermode::Mode xfermode,
                                     SkRect* bounds,
-                                    skia::RefPtr<SkColorFilter> cf) {
+                                    skia::RefPtr<SkColorFilter> cf,
+                                    bool lcd_text_requires_opaque_layer) {
   alpha_ = alpha;
   xfermode_ = xfermode;
   has_bounds_ = !!bounds;
   if (bounds)
     bounds_ = SkRect(*bounds);
   color_filter_ = std::move(cf);
+  lcd_text_requires_opaque_layer_ = lcd_text_requires_opaque_layer;
 }
 
 void CompositingDisplayItem::ToProtobuf(proto::DisplayItem* proto) const {
   proto->set_type(proto::DisplayItem::Type_Compositing);
 
   proto::CompositingDisplayItem* details = proto->mutable_compositing_item();
   details->set_alpha(static_cast<uint32_t>(alpha_));
   details->set_mode(SkXfermodeModeToProto(xfermode_));
   if (has_bounds_)
     RectFToProto(gfx::SkRectToRectF(bounds_), details->mutable_bounds());
 
   if (color_filter_) {
     skia::RefPtr<SkData> data =
         skia::AdoptRef(SkValidatingSerializeFlattenable(color_filter_.get()));
     if (data->size() > 0)
       details->set_color_filter(data->data(), data->size());
   }
+
+  details->set_lcd_text_requires_opaque_layer(lcd_text_requires_opaque_layer_);
 }
 
 void CompositingDisplayItem::Raster(
     SkCanvas* canvas,
     const gfx::Rect& canvas_target_playback_rect,
     SkPicture::AbortCallback* callback) const {
   SkPaint paint;
   paint.setXfermodeMode(xfermode_);
   paint.setAlpha(alpha_);
   paint.setColorFilter(color_filter_.get());
-  canvas->saveLayer(has_bounds_ ? &bounds_ : nullptr, &paint);
+  const SkRect* bounds = has_bounds_ ? &bounds_ : nullptr;
+  if (lcd_text_requires_opaque_layer_)
+    canvas->saveLayer(bounds, &paint);
+  else
+    canvas->saveLayerPreserveLCDTextRequests(bounds, &paint);
 }
 
 void CompositingDisplayItem::AsValueInto(
     const gfx::Rect& visual_rect,
     base::trace_event::TracedValue* array) const {
   array->AppendString(base::StringPrintf(
       "CompositingDisplayItem alpha: %d, xfermode: %d, visualRect: [%s]",
       alpha_, xfermode_, visual_rect.ToString().c_str()));
   if (has_bounds_)
     array->AppendString(base::StringPrintf(
@@ skipping 34 matching lines @@
   array->AppendString(
       base::StringPrintf("EndCompositingDisplayItem visualRect: [%s]",
                          visual_rect.ToString().c_str()));
 }
 
 size_t EndCompositingDisplayItem::ExternalMemoryUsage() const {
   return 0;
 }
 
 }  // namespace cc