GTK: Move CairoCachedSurface from being owned by GtkThemeService to gfx::Image.

ui/gfx/image/image_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 "base/memory/scoped_ptr.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/gfx/image/image.h"
 #include "ui/gfx/image/image_unittest_util.h"
 
@@ skipping 123 matching lines @@
   GdkPixbuf* pixbuf;
 
   {
     gfx::Image image(gt::CreateBitmap(25, 25));
     pixbuf = image.CopyGdkPixbuf();
   }
 
   EXPECT_TRUE(pixbuf);
   g_object_unref(pixbuf);
 }
+
+TEST_F(ImageTest, SkiaToCairoCreatesGdk) {
+  gfx::Image image(gt::CreateBitmap(25, 25));
+  EXPECT_FALSE(image.HasRepresentation(gfx::Image::kImageRepGdk));
+  EXPECT_TRUE(image.ToCairo());
+  EXPECT_TRUE(image.HasRepresentation(gfx::Image::kImageRepGdk));
+}
 #endif
 
 #if defined(OS_MACOSX)
 TEST_F(ImageTest, SkiaToCocoaCopy) {
   NSImage* ns_image;
 
   {
     gfx::Image image(gt::CreateBitmap(25, 25));
     ns_image = image.CopyNSImage();
   }
@@ skipping 90 matching lines @@
   // Sanity check.
   EXPECT_EQ(1u, image.RepresentationCount());
   EXPECT_EQ(2u, image.GetNumberOfSkBitmaps());
 }
 
 // Integration tests with UI toolkit frameworks require linking against the
 // Views library and cannot be here (gfx_unittests doesn't include it). They
 // instead live in /chrome/browser/ui/tests/ui_gfx_image_unittest.cc.
 
 }  // namespace