ui/gfx: Make use of SkAutoLockPixels to automatically lock and unlock bitmap pixels properly.

ui/gfx/gtk_util.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/gtk_util.h"
 
 #include <gdk/gdk.h>
 #include <gtk/gtk.h>
 #include <stdlib.h>
 
@@ skipping 64 matching lines @@
   gtk_init(&argc, &argv_pointer);
   for (size_t i = 0; i < args.size(); ++i) {
     free(argv[i]);
   }
 }
 
 GdkPixbuf* GdkPixbufFromSkBitmap(const SkBitmap* bitmap) {
   if (bitmap->isNull())
     return NULL;
 
-  bitmap->lockPixels();
+  SkAutoLockPixels lock_pixels(*bitmap);
 
   int width = bitmap->width();
   int height = bitmap->height();
   int stride = bitmap->rowBytes();
 
   // SkBitmaps are premultiplied, we need to unpremultiply them.
   const int kBytesPerPixel = 4;
   uint8* divided = static_cast<uint8*>(malloc(height * stride));
 
   for (int y = 0, i = 0; y < height; y++) {
@@ skipping 19 matching lines @@
 
   // This pixbuf takes ownership of our malloc()ed data and will
   // free it for us when it is destroyed.
   GdkPixbuf* pixbuf = gdk_pixbuf_new_from_data(
       divided,
       GDK_COLORSPACE_RGB,  // The only colorspace gtk supports.
       true,  // There is an alpha channel.
       8,
       width, height, stride, &FreePixels, divided);
 
-  bitmap->unlockPixels();
   return pixbuf;
 }
 
 void SubtractRectanglesFromRegion(GdkRegion* region,
                                   const std::vector<Rect>& cutouts) {
   for (size_t i = 0; i < cutouts.size(); ++i) {
     GdkRectangle rect = cutouts[i].ToGdkRectangle();
     GdkRegion* rect_region = gdk_region_rectangle(&rect);
     gdk_region_subtract(region, rect_region);
     // TODO(deanm): It would be nice to be able to reuse the GdkRegion here.
@@ skipping 29 matching lines @@
       "  GtkDialog::button-spacing = 6\n"
       "  GtkDialog::content-area-spacing = 18\n"
       "  GtkDialog::content-area-border = 0\n"
       "}\n"
       "widget \"about-dialog\" style : application \"about-dialog\"\n";
 
   gtk_rc_parse_string(kRCText);
 }
 
 }  // namespace gfx