Add support for adding 256x256 pngs to Windows .ico files.

ui/gfx/icon_util.h

 // Copyright (c) 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 UI_GFX_ICON_UTIL_H_
 #define UI_GFX_ICON_UTIL_H_
 
 #include <windows.h>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/gtest_prod_util.h"
 #include "ui/base/ui_export.h"
 #include "ui/gfx/point.h"
 #include "ui/gfx/size.h"
 
 namespace gfx {
 class Size;
 }
 class FilePath;
 class SkBitmap;
 
@@ skipping 51 matching lines @@
 
   // Given a valid HICON handle representing an icon, this function converts
   // the icon into an SkBitmap object containing an ARGB bitmap using the
   // dimensions of HICON. If the function cannot convert the icon to a bitmap
   // (most probably due to an invalid parameter), the return value is NULL.
   //
   // The client owns the returned bitmap object and is responsible for deleting
   // it when it is no longer needed.
   static SkBitmap* CreateSkBitmapFromHICON(HICON icon);
 
-  // Given an initialized SkBitmap object and a file name, this function
-  // creates a .ico file with the given name using the provided bitmap. The
-  // icon file is created with multiple icon images of varying predefined
-  // dimensions because Windows uses different image sizes when loading icons,
+  // Creates Windows .ico file at |icon_path|. The icon file is created with
+  // multiple BMP representations at varying predefined dimensions (by resizing
+  // |bitmap|) because Windows uses different image sizes when loading icons,
   // depending on where the icon is drawn (ALT+TAB window, desktop shortcut,
-  // Quick Launch, etc.). |icon_file_name| needs to specify the full path for
-  // the desired .ico file.
+  // Quick Launch, etc.).
+  //
+  // To create an icon file containing a 256x256 PNG entry, which is used by
+  // Vista+ for high res icons, specify a non-empty 256x256 SkBitmap for the
+  // |large_bitmap| parameter.
   //
   // The function returns true on success and false otherwise.
   static bool CreateIconFileFromSkBitmap(const SkBitmap& bitmap,
+                                         const SkBitmap& large_bitmap,
                                          const FilePath& icon_path);
 
   // Creates a cursor of the specified size from the DIB passed in.
   // Returns the cursor on success or NULL on failure.
   static HICON CreateCursorFromDIB(const gfx::Size& icon_size,
                                    const gfx::Point& hotspot,
                                    const void* dib_bits,
                                    size_t dib_size);
 
  private:
@@ skipping 28 matching lines @@
 
   // Contains the actual icon image.
   struct ICONIMAGE {
     BITMAPINFOHEADER icHeader;
     RGBQUAD icColors[1];
     BYTE icXOR[1];
     BYTE icAND[1];
   };
 #pragma pack(pop)
 
+  FRIEND_TEST_ALL_PREFIXES(IconUtilTest, TestCreateIconFileWithLargeBitmap);
+
   // Used for indicating that the .ico contains an icon (rather than a cursor)
   // image. This value is set in the |idType| field of the ICONDIR structure.
   static const int kResourceTypeIcon = 1;
 
   // The dimensions of the icon images we insert into the .ico file.
   static const int icon_dimensions_[];
 
   // Returns true if any pixel in the given pixels buffer has an non-zero alpha.
   static bool PixelsHaveAlpha(const uint32* pixels, size_t num_pixels);
 
@@ skipping 56 matching lines @@
   // A helper function of CreateSkBitmapFromHICON.
   static SkBitmap CreateSkBitmapFromHICONHelper(HICON icon,
                                                 const gfx::Size& s);
 
   // Prevent clients from instantiating objects of that class by declaring the
   // ctor/dtor as private.
   DISALLOW_IMPLICIT_CONSTRUCTORS(IconUtil);
 };
 
 #endif  // UI_GFX_ICON_UTIL_H_