Optionally clear PlatformCanvas instances.

skia/ext/bitmap_platform_device_mac_unittest.cc

 // Copyright (c) 2011 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 "skia/ext/bitmap_platform_device_mac.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "skia/ext/skia_utils_mac.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/include/core/SkMatrix.h"
 #include "third_party/skia/include/core/SkRegion.h"
 #include "third_party/skia/include/core/SkClipStack.h"
 
 namespace skia {
 
 const int kWidth = 400;
 const int kHeight = 300;
 
 class BitmapPlatformDeviceMacTest : public testing::Test {
  public:
   BitmapPlatformDeviceMacTest() {
     bitmap_.reset(BitmapPlatformDevice::Create(
         NULL, kWidth, kHeight, /*is_opaque=*/true));
+    bitmap_->accessBitmap(true).eraseARGB(0, 0, 0, 0);
   }
 
   scoped_ptr<BitmapPlatformDevice> bitmap_;
 };
 
 TEST_F(BitmapPlatformDeviceMacTest, ClipRectTransformWithTranslate) {
   SkMatrix transform;
   transform.setTranslate(50, 140);
 
   SkClipStack ignore;
@@ skipping 26 matching lines @@
   CGContextRef context = bitmap_->GetBitmapContext();
   SkRect clip_rect = gfx::CGRectToSkRect(CGContextGetClipBoundingBox(context));
   transform.mapRect(&clip_rect);
   EXPECT_EQ(0, clip_rect.fLeft);
   EXPECT_EQ(0, clip_rect.fTop);
   EXPECT_EQ(kWidth, clip_rect.width());
   EXPECT_EQ(kHeight, clip_rect.height());
 }
 
 }  // namespace skia