Allow background tab titles to use LCD AA.

This involves plumbing an additional flag through CompositingRecorder and
CompositingDisplayItem to use the new Skia functionality just added for this.

BUG=none
TEST=Titles on background tabs should use LCD antialiasing.
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1506203008

Cr-Commit-Position: refs/heads/master@{#364903}

3 files changed, 29 insertions, 11 deletions

diff --git a/cc/playback/compositing_display_item.cc b/cc/playback/compositing_display_item.cc
index b9cd395..3c6e8b0 100644
--- a/cc/playback/compositing_display_item.cc
+++ b/cc/playback/compositing_display_item.cc
@@ -19,11 +19,14 @@
 
 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(
@@ -47,7 +50,11 @@ CompositingDisplayItem::CompositingDisplayItem(
     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() {
@@ -56,13 +63,15 @@ 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 {
@@ -80,6 +89,8 @@ void CompositingDisplayItem::ToProtobuf(proto::DisplayItem* proto) const {
     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(
@@ -90,7 +101,11 @@ void CompositingDisplayItem::Raster(
   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(
diff --git a/cc/playback/compositing_display_item.h b/cc/playback/compositing_display_item.h
index 9512189..e0dd8701 100644
--- a/cc/playback/compositing_display_item.h
+++ b/cc/playback/compositing_display_item.h
@@ -23,7 +23,8 @@ class CC_EXPORT CompositingDisplayItem : public DisplayItem {
   CompositingDisplayItem(uint8_t alpha,
                          SkXfermode::Mode xfermode,
                          SkRect* bounds,
-                         skia::RefPtr<SkColorFilter> color_filter);
+                         skia::RefPtr<SkColorFilter> color_filter,
+                         bool lcd_text_requires_opaque_layer);
   explicit CompositingDisplayItem(const proto::DisplayItem& proto);
   ~CompositingDisplayItem() override;
 
@@ -42,13 +43,15 @@ class CC_EXPORT CompositingDisplayItem : public DisplayItem {
   void SetNew(uint8_t alpha,
               SkXfermode::Mode xfermode,
               SkRect* bounds,
-              skia::RefPtr<SkColorFilter> color_filter);
+              skia::RefPtr<SkColorFilter> color_filter,
+              bool lcd_text_requires_opaque_layer);
 
   uint8_t alpha_;
   SkXfermode::Mode xfermode_;
   bool has_bounds_;
   SkRect bounds_;
   skia::RefPtr<SkColorFilter> color_filter_;
+  bool lcd_text_requires_opaque_layer_;
 };
 
 class CC_EXPORT EndCompositingDisplayItem : public DisplayItem {
diff --git a/cc/playback/display_item_list_unittest.cc b/cc/playback/display_item_list_unittest.cc
index b56a79d..e1e2bd2 100644
--- a/cc/playback/display_item_list_unittest.cc
+++ b/cc/playback/display_item_list_unittest.cc
@@ -185,7 +185,7 @@ TEST(DisplayItemListTest, SerializeCompositingItem) {
   skia::RefPtr<SkColorFilter> filter = skia::AdoptRef(
       SkColorFilter::CreateLightingFilter(SK_ColorRED, SK_ColorGREEN));
   list->CreateAndAppendItem<CompositingDisplayItem>(
-      kVisualRect, 150, SkXfermode::Mode::kDst_Mode, nullptr, filter);
+      kVisualRect, 150, SkXfermode::Mode::kDst_Mode, nullptr, filter, false);
 
   // Build the second DrawingDisplayItem.
   AppendSecondSerializationTestPicture(list, layer_size);