Add non-member non-mutating methods for common gfx::Rect operations.

ui/gfx/image/image_skia_operations.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_operations.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "skia/ext/image_operations.h"
 #include "skia/ext/platform_canvas.h"
@@ skipping 270 matching lines @@
       : image_(image),
         subset_bounds_(subset_bounds) {
   }
 
   virtual ~ExtractSubsetImageSource() {
   }
 
   // gfx::ImageSkiaSource overrides:
   virtual ImageSkiaRep GetImageForScale(ui::ScaleFactor scale_factor) OVERRIDE {
     ImageSkiaRep image_rep = image_.GetRepresentation(scale_factor);
-    gfx::RectF scaled_subset_bounds = subset_bounds_;
-    scaled_subset_bounds.Scale(
-        ui::GetScaleFactorScale(image_rep.scale_factor()));
-    SkIRect subset_bounds_in_pixel = RectToSkIRect(
-        ToEnclosingRect(scaled_subset_bounds));
+    SkIRect subset_bounds_in_pixel = RectToSkIRect(ToEnclosingRect(gfx::Scale(
+        subset_bounds_, ui::GetScaleFactorScale(image_rep.scale_factor()))));
     SkBitmap dst;
     bool success = image_rep.sk_bitmap().extractSubset(&dst,
                                                        subset_bounds_in_pixel);
     DCHECK(success);
     return gfx::ImageSkiaRep(dst, image_rep.scale_factor());
   }
 
  private:
   const gfx::ImageSkia image_;
   const gfx::Rect subset_bounds_;
@@ skipping 119 matching lines @@
 // static
 ImageSkia ImageSkiaOperations::CreateButtonBackground(SkColor color,
                                                       const ImageSkia& image,
                                                       const ImageSkia& mask) {
   return ImageSkia(new ButtonImageSource(color, image, mask), mask.size());
 }
 
 // static
 ImageSkia ImageSkiaOperations::ExtractSubset(const ImageSkia& image,
                                              const Rect& subset_bounds) {
-  gfx::Rect clipped_bounds = subset_bounds;
-  clipped_bounds.Intersect(gfx::Rect(image.size()));
+  gfx::Rect clipped_bounds =
+      gfx::Intersection(subset_bounds, gfx::Rect(image.size()));
   if (image.isNull() || clipped_bounds.IsEmpty()) {
     return ImageSkia();
   }
 
   return ImageSkia(new ExtractSubsetImageSource(image, clipped_bounds),
                    clipped_bounds.size());
 }
 
 // static
 ImageSkia ImageSkiaOperations::CreateResizedImage(
     const ImageSkia& source,
     skia::ImageOperations::ResizeMethod method,
     const Size& target_dip_size) {
   return ImageSkia(new ResizeSource(source, method, target_dip_size),
                    target_dip_size);
 }
 
 // static
 ImageSkia ImageSkiaOperations::CreateImageWithDropShadow(
     const ImageSkia& source,
     const ShadowValues& shadows) {
   const gfx::Insets shadow_padding = -gfx::ShadowValue::GetMargin(shadows);
   gfx::Size shadow_image_size = source.size();
   shadow_image_size.Enlarge(shadow_padding.width(),
                             shadow_padding.height());
   return ImageSkia(new DropShadowSource(source, shadows), shadow_image_size);
 }
 
 }  // namespace gfx