Revert 137622 - Fix a couple of bugs with the image skia implementation

ui/gfx/image/image_skia.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_skia.h"
 
 #include <limits>
 #include <cmath>
 
 #include "base/logging.h"
@@ skipping 73 matching lines @@
 ImageSkia::~ImageSkia() {
 }
 
 void ImageSkia::AddBitmapForScale(const SkBitmap& bitmap,
                                   float dip_scale_factor) {
   DCHECK(!bitmap.isNull());
 
   if (isNull()) {
     Init(bitmap, dip_scale_factor);
   } else {
-    // Currently data packs include 1x scale images whenever a different scale
-    // image is unavailable. As |dip_scale_factor| is derived from the data
-    // pack, sometimes |dip_scale_factor| is incorrect.
-    // TODO(pkotwicz): Fix this and add DCHECK.
+    // We currently assume that the bitmap size = 1x size * |dip_scale_factor|.
+    // TODO(pkotwicz): Do something better because of rounding errors when
+    // |dip_scale_factor| is not an int.
+    // TODO(pkotwicz): Remove DCHECK for dip_scale_factor == 1.0f once
+    // image_loading_tracker correctly handles multiple sized images.
+    DCHECK(dip_scale_factor == 1.0f ||
+              static_cast<int>(width() * dip_scale_factor) == bitmap.width());
+    DCHECK(dip_scale_factor == 1.0f ||
+              static_cast<int>(height() * dip_scale_factor) == bitmap.height());
     storage_->AddBitmap(bitmap);
   }
 }
 
 const SkBitmap& ImageSkia::GetBitmapForScale(float x_scale_factor,
                                              float y_scale_factor,
                                              float* bitmap_scale_factor) const {
 
   if (empty())
     return *null_bitmap_;
@@ skipping 70 matching lines @@
     storage_ = NULL;
     return;
   }
   storage_ = new internal::ImageSkiaStorage();
   storage_->set_size(gfx::Size(static_cast<int>(bitmap.width() / scale_factor),
       static_cast<int>(bitmap.height() / scale_factor)));
   storage_->AddBitmap(bitmap);
 }
 
 }  // namespace gfx