Use SaveLayerWithFlags to avoid cpu bitmaps in RoundedCornersImageSource

chrome/browser/ui/app_list/extension_app_item.cc

 // Copyright (c) 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 "chrome/browser/ui/app_list/extension_app_item.h"
 
 #include <stddef.h>
 
 #include "base/macros.h"
 #include "build/build_config.h"
@@ skipping 66 matching lines @@
   ~RoundedCornersImageSource() override {}
 
  private:
   // gfx::CanvasImageSource overrides:
   void Draw(gfx::Canvas* canvas) override {
     // The radius used to round the app icon.
     const size_t kRoundingRadius = 2;
 
     canvas->DrawImageInt(icon_, 0, 0);
 
-    SkBitmap mask_bitmap;
-    mask_bitmap.allocN32Pixels(icon_.width(), icon_.height(), false);
-    SkCanvas mask_canvas(mask_bitmap);
-    mask_canvas.clear(SK_ColorTRANSPARENT);
-    SkPaint mask_paint;
-    mask_paint.setAntiAlias(true);
-    mask_paint.setColor(SK_ColorWHITE);
-    mask_canvas.drawRoundRect(
-        gfx::RectToSkRect(gfx::Rect(icon_.width(), icon_.height())),
-        kRoundingRadius, kRoundingRadius, mask_paint);
-
     cc::PaintFlags masking_flags;
     masking_flags.setBlendMode(SkBlendMode::kDstIn);
-    canvas->sk_canvas()->drawBitmap(mask_bitmap, 0, 0, &masking_flags);
+    canvas->SaveLayerWithFlags(masking_flags);
+
+    cc::PaintFlags mask_flags;
+    mask_flags.setAntiAlias(true);
+    mask_flags.setColor(SK_ColorWHITE);
+    canvas->DrawRoundRect(gfx::Rect(icon_.width(), icon_.height()),
+                          kRoundingRadius, mask_flags);
+
+    canvas->Restore();
   }
 
   gfx::ImageSkia icon_;
 
   DISALLOW_COPY_AND_ASSIGN(RoundedCornersImageSource);
 };
 
 }  // namespace
 
 ExtensionAppItem::ExtensionAppItem(
@@ skipping 196 matching lines @@
 // static
 const char ExtensionAppItem::kItemType[] = "ExtensionAppItem";
 
 const char* ExtensionAppItem::GetItemType() const {
   return ExtensionAppItem::kItemType;
 }
 
 void ExtensionAppItem::ExecuteLaunchCommand(int event_flags) {
   Launch(event_flags);
 }