Remove forward declarations of unused ImageRepGdk and ImageRepCairo

ui/gfx/image/image.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 "ui/gfx/image/image.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 84 matching lines @@
       !gfx::PNGCodec::EncodeBGRASkBitmap(image_skia_rep.sk_bitmap(), false,
           &png_bytes->data())) {
     return NULL;
   }
   return png_bytes;
 }
 #endif
 
 class ImageRepPNG;
 class ImageRepSkia;
-class ImageRepGdk;
 class ImageRepCocoa;
 class ImageRepCocoaTouch;
 
 // An ImageRep is the object that holds the backing memory for an Image. Each
 // RepresentationType has an ImageRep subclass that is responsible for freeing
 // the memory that the ImageRep holds. When an ImageRep is created, it expects
 // to take ownership of the image, without having to retain it or increase its
 // reference count.
 class ImageRep {
  public:
@@ skipping 574 matching lines @@
 
 #if defined(OS_MACOSX)  && !defined(OS_IOS)
 void Image::SetSourceColorSpace(CGColorSpaceRef color_space) {
   if (storage_.get())
     storage_->set_default_representation_color_space(color_space);
 }
 #endif  // defined(OS_MACOSX) && !defined(OS_IOS)
 
 Image::RepresentationType Image::DefaultRepresentationType() const {
   CHECK(storage_.get());
-  RepresentationType default_type = storage_->default_representation_type();
-  // The conversions above assume that the default representation type is never
-  // kImageRepCairo.
-  DCHECK_NE(default_type, kImageRepCairo);
-  return default_type;
+  return storage_->default_representation_type();
 }
 
 internal::ImageRep* Image::GetRepresentation(
     RepresentationType rep_type, bool must_exist) const {
   CHECK(storage_.get());
   RepresentationMap::iterator it = storage_->representations().find(rep_type);
   if (it == storage_->representations().end()) {
     CHECK(!must_exist);
     return NULL;
   }
   return it->second;
 }
 
 void Image::AddRepresentation(internal::ImageRep* rep) const {
   CHECK(storage_.get());
   storage_->representations().insert(std::make_pair(rep->type(), rep));
 }
 
 }  // namespace gfx