cc: Adding support for RGBA_4444 tile textures

cc/resources/platform_color.h

 // Copyright 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.
 
 #ifndef CC_RESOURCES_PLATFORM_COLOR_H_
 #define CC_RESOURCES_PLATFORM_COLOR_H_
 
 #include "base/basictypes.h"
 #include "base/logging.h"
+#include "cc/resources/resource_format.h"
 #include "third_party/khronos/GLES2/gl2.h"
 #include "third_party/khronos/GLES2/gl2ext.h"
 #include "third_party/skia/include/core/SkTypes.h"
 
 namespace cc {
 
 class PlatformColor {
  public:
   enum SourceDataFormat {
     SOURCE_FORMAT_RGBA8,
     SOURCE_FORMAT_BGRA8
   };
 
   static SourceDataFormat Format() {
     return SK_B32_SHIFT ? SOURCE_FORMAT_RGBA8 : SOURCE_FORMAT_BGRA8;
   }
 
   // Returns the most efficient texture format for this platform.
-  static GLenum BestTextureFormat(bool supports_bgra8888) {
+  static ResourceFormat BestTextureFormat(bool supports_bgra8888) {
     switch (Format()) {
       case SOURCE_FORMAT_BGRA8:
-        if (supports_bgra8888)
-          return GL_BGRA_EXT;
-        return GL_RGBA;
+        return (supports_bgra8888) ? BGRA_8888 : RGBA_8888;
       case SOURCE_FORMAT_RGBA8:
-        return GL_RGBA;
+        return RGBA_8888;
     }
     NOTREACHED();
-    return GL_RGBA;
+    return RGBA_8888;
   }
 
   // Return true if the given texture format has the same component order
   // as the color on this platform.
-  static bool SameComponentOrder(GLenum texture_format) {
+  static bool SameComponentOrder(ResourceFormat format) {
     switch (Format()) {
       case SOURCE_FORMAT_RGBA8:
-        return texture_format == GL_RGBA;
+        return format == RGBA_8888 || format == RGBA_4444;
       case SOURCE_FORMAT_BGRA8:
-        return texture_format == GL_BGRA_EXT;
+        return format == BGRA_8888;
     }
     NOTREACHED();
     return false;
   }
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PlatformColor);
 };
 
 }  // namespace cc
 
 #endif  // CC_RESOURCES_PLATFORM_COLOR_H_