Crop images from custom themes before storing them into the theme pack

chrome/browser/themes/browser_theme_pack.h

Index: chrome/browser/themes/browser_theme_pack.h
diff --git a/chrome/browser/themes/browser_theme_pack.h b/chrome/browser/themes/browser_theme_pack.h
index ce5b318c97e156e22c429e14874904807d9cefd4..0911319a69e2a03a6d0f06478eccc7c35a590507 100644
--- a/chrome/browser/themes/browser_theme_pack.h
+++ b/chrome/browser/themes/browser_theme_pack.h
@@ -84,8 +84,9 @@ class BrowserThemePack : public base::RefCountedThreadSafe<
   bool GetColor(int id, SkColor* color) const;
   bool GetDisplayProperty(int id, int* result) const;
 
-  // Returns an image if we have a custom image for |id|, otherwise NULL.
-  const gfx::Image* GetImageNamed(int id) const;
+  // Returns the theme pack image for |id|. Returns an empty image if an image
+  // is not found.
+  gfx::Image GetImageNamed(int id);
 
   // Returns the raw PNG encoded data for IDR_THEME_NTP_*. This method is only
   // supposed to work for the NTP attribution and background resources.
@@ -105,10 +106,8 @@ class BrowserThemePack : public base::RefCountedThreadSafe<
   friend class base::DeleteHelper<BrowserThemePack>;
   friend class BrowserThemePackTest;
 
-  // Cached images. We cache all retrieved and generated images and keep
-  // track of the pointers. We own these and will delete them when we're done
-  // using them.
-  typedef std::map<int, const gfx::Image*> ImageCache;
+  // Cached images.
+  typedef std::map<int, gfx::Image> ImageCache;
 
   // The raw PNG memory associated with a certain id.
   typedef std::map<int, scoped_refptr<base::RefCountedMemory> > RawImages;
@@ -161,6 +160,11 @@ class BrowserThemePack : public base::RefCountedThreadSafe<
   // Source and destination is |images|.
   void CreateImages(ImageCache* images) const;
 
+  // Crops images down to a size such that most of the cropped image will be
+  // displayed in the UI. Cropping is useful because images from custom themes
+  // can be of any size. Source and destination is |images|.
+  void CropImages(ImageCache* images) const;
+
   // Creates tinted and composited frame images. Source and destination is
   // |images|.
   void CreateFrameImages(ImageCache* images) const;
@@ -256,7 +260,7 @@ class BrowserThemePack : public base::RefCountedThreadSafe<
   // Loaded images. These are loaded from |image_memory_|, from |data_pack_|,
   // and by BuildFromExtension(). These images should only be accessed on the UI
   // thread.
-  mutable ImageCache images_on_ui_thread_;
+  ImageCache images_on_ui_thread_;
 
   // Cache of images created in BuildFromExtension(). Once the theme pack is
   // created, this cache should only be accessed on the file thread. There