Make skia.mojom.Bitmap use shared buffer

ui/gfx/image/mojo/image_traits_unittest.cc

Index: ui/gfx/image/mojo/image_traits_unittest.cc
diff --git a/ui/gfx/image/mojo/image_traits_unittest.cc b/ui/gfx/image/mojo/image_traits_unittest.cc
index bce6866e21ebd0ea9eb6ce10a5e33c07ab808fcb..0d7b43c36483369943c429e5be1e089e76d34c69 100644
--- a/ui/gfx/image/mojo/image_traits_unittest.cc
+++ b/ui/gfx/image/mojo/image_traits_unittest.cc
@@ -79,7 +79,7 @@ TEST_F(ImageTraitsTest, NullImageSkiaRep) {
   EXPECT_TRUE(output.is_null());
 }
 
-TEST_F(ImageTraitsTest, EmptyImageSkiaRep) {
+TEST_F(ImageTraitsTest, EmptyImageSkiaRepBecomesNull) {
   SkBitmap empty_bitmap;
   empty_bitmap.allocN32Pixels(0, 0);
   // Empty SkBitmap is not null.
@@ -93,8 +93,10 @@ TEST_F(ImageTraitsTest, EmptyImageSkiaRep) {
   ImageSkiaRep output(gfx::Size(1, 1), 1.0f);
   ASSERT_FALSE(output.is_null());
   service()->EchoImageSkiaRep(empty_rep, &output);
-  EXPECT_TRUE(empty_rep.sk_bitmap().drawsNothing());
-  EXPECT_TRUE(test::AreBitmapsEqual(empty_rep.sk_bitmap(), output.sk_bitmap()));
+  // After transport, output rep has no underlying buffer but has valid size.
+  EXPECT_TRUE(output.is_null());

[msw, 2017/03/25 00:59:52]

Odd that this doesn't match empty_rep.is_null()...

+  EXPECT_EQ(empty_rep.pixel_size(), output.pixel_size());
+  EXPECT_EQ(empty_rep.scale(), output.scale());
 }
 
 TEST_F(ImageTraitsTest, ImageSkiaRep) {
@@ -152,21 +154,6 @@ TEST_F(ImageTraitsTest, ImageSkia) {
   EXPECT_TRUE(test::AreImagesEqual(Image(output), Image(image)));
 }
 
-TEST_F(ImageTraitsTest, EmptyRepPreserved) {
-  const gfx::Size kSize(1, 2);
-  ImageSkia image(new TestImageSkiaSource(kSize), kSize);
-  image.GetRepresentation(1.0f);
-
-  SkBitmap empty_bitmap;
-  empty_bitmap.allocN32Pixels(0, 0);
-  image.AddRepresentation(ImageSkiaRep(empty_bitmap, 2.0f));
-
-  ImageSkia output;
-  service()->EchoImageSkia(image, &output);
-
-  EXPECT_TRUE(test::AreImagesEqual(Image(output), Image(image)));
-}
-
 TEST_F(ImageTraitsTest, ImageSkiaWithOperations) {
   const gfx::Size kSize(32, 32);
   ImageSkia image(new TestImageSkiaSource(kSize), kSize);