Eliminate HICON leaks caused by creating icons from bitmap image.

ui/gfx/icon_util.h

 // 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.
 
 #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/memory/scoped_ptr.h"
+#include "base/win/scoped_gdi_object.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/gfx_export.h"
 
 namespace base {
 class FilePath;
 }
 
 namespace gfx {
 class ImageFamily;
@@ skipping 11 matching lines @@
 //
 //   SkBitmap bitmap;
 //
 //   // Fill |bitmap| with valid data
 //   bitmap.setConfig(...);
 //   bitmap.allocPixels();
 //
 //   ...
 //
 //   // Convert the bitmap into a Windows HICON
-//   HICON icon = IconUtil::CreateHICONFromSkBitmap(bitmap);
-//   if (icon == NULL) {
+//   base::win::ScopedHICON icon(IconUtil::CreateHICONFromSkBitmap(bitmap));
+//   if (!icon.is_valid()) {
 //     // Handle error
 //     ...
 //   }
 //
 //   // Use the icon with a WM_SETICON message
 //   ::SendMessage(hwnd, WM_SETICON, static_cast<WPARAM>(ICON_BIG),
-//                 reinterpret_cast<LPARAM>(icon));
-//
-//   // Destroy the icon when we are done
-//   ::DestroyIcon(icon);
+//                 reinterpret_cast<LPARAM>(icon.get()));
 //
 ///////////////////////////////////////////////////////////////////////////////
 class GFX_EXPORT IconUtil {
  public:
   // ATOMIC_WRITE ensures that a partially written icon won't be created even if
   // Chrome crashes part way through, but ATOMIC_WRITE is more expensive than
   // NORMAL_WRITE. See CreateIconFileFromImageFamily. ATOMIC_WRITE is the
   // default for historical reasons.
   enum WriteType { ATOMIC_WRITE, NORMAL_WRITE };
   // The size of the large icon entries in .ico files on Windows Vista+.
@@ skipping 12 matching lines @@
   static const size_t kNumIconDimensions;
   // The number of elements in kIconDimensions <= kMediumIconSize.
   static const size_t kNumIconDimensionsUpToMediumSize;
 
   // Given an SkBitmap object, the function converts the bitmap to a Windows
   // icon and returns the corresponding HICON handle. If the function cannot
   // convert the bitmap, NULL is returned.
   //
   // The client is responsible for destroying the icon when it is no longer
   // needed by calling ::DestroyIcon().
-  static HICON CreateHICONFromSkBitmap(const SkBitmap& bitmap);
+  static base::win::ScopedHICON CreateHICONFromSkBitmap(const SkBitmap& bitmap);
 
   // Given a valid HICON handle representing an icon, this function converts
   // the icon into an SkBitmap object containing an ARGB bitmap using the
   // dimensions specified in |s|. |s| must specify valid dimensions (both
   // width() an height() must be greater than zero). 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.
@@ skipping 29 matching lines @@
   //
   // The function returns true on success and false otherwise. Returns false if
   // |image_family| is empty.
   static bool CreateIconFileFromImageFamily(
       const gfx::ImageFamily& image_family,
       const base::FilePath& icon_path,
       WriteType write_type = ATOMIC_WRITE);
 
   // 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);
+  static base::win::ScopedHICON CreateCursorFromDIB(const gfx::Size& icon_size,
+                                                    const gfx::Point& hotspot,
+                                                    const void* dib_bits,
+                                                    size_t dib_size);
 
  private:
   // The icon format is published in the MSDN but there is no definition of
   // the icon file structures in any of the Windows header files so we need to
   // define these structure within the class. We must make sure we use 2 byte
   // packing so that the structures are laid out properly within the file.
   // See: http://msdn.microsoft.com/en-us/library/ms997538.aspx
 #pragma pack(push)
 #pragma pack(2)
 
@@ skipping 112 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_