Adds a new constructor for gfx::Image on iOS.

ui/gfx/image/image.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.h"
 
 #include <algorithm>
 #include <set>
 #include <utility>
 
@@ skipping 402 matching lines @@
 
 Image::Image(const ImageSkia& image) {
   if (!image.isNull()) {
     storage_ = new internal::ImageStorage(Image::kImageRepSkia);
     AddRepresentation(
         base::MakeUnique<internal::ImageRepSkia>(new ImageSkia(image)));
   }
 }
 
 #if defined(OS_IOS)
-Image::Image(UIImage* image)
+Image::Image(UIImage* image) : Image(image, false) {}
+
+Image::Image(UIImage* image, bool retain_argument)
     : storage_(new internal::ImageStorage(Image::kImageRepCocoaTouch)) {
-  if (image)
+  if (image) {
+    if (retain_argument)
+      base::mac::NSObjectRetain(image);
     AddRepresentation(base::MakeUnique<internal::ImageRepCocoaTouch>(image));
+  }
 }
 #elif defined(OS_MACOSX)
 Image::Image(NSImage* image) {
   if (image) {
     storage_ = new internal::ImageStorage(Image::kImageRepCocoa);
     AddRepresentation(base::MakeUnique<internal::ImageRepCocoa>(image));
   }
 }
 #endif
 
@@ skipping 319 matching lines @@
       storage_->representations().insert(std::make_pair(type, std::move(rep)));
 
   // insert should not fail (implies that there was already a representation of
   // that type in the map).
   CHECK(result.second) << "type was already in map.";
 
   return result.first->second.get();
 }
 
 }  // namespace gfx