Changes behavior of iOS-specific gfx::Image constructor.

ui/gfx/image/image.cc

Index: ui/gfx/image/image.cc
diff --git a/ui/gfx/image/image.cc b/ui/gfx/image/image.cc
index e3bcefcea217b644f8d2dda379b99cce31f89bce..12254c17def66a5b46fb45db8257732cf14af173 100644
--- a/ui/gfx/image/image.cc
+++ b/ui/gfx/image/image.cc
@@ -420,7 +420,7 @@ Image::Image(const ImageSkia& image) {
 }
 
 #if defined(OS_IOS)
-Image::Image(UIImage* image) : Image(image, base::scoped_policy::ASSUME) {}
+Image::Image(UIImage* image) : Image(image, base::scoped_policy::RETAIN) {}
 
 Image::Image(UIImage* image, base::scoped_policy::OwnershipPolicy policy)
     : storage_(new internal::ImageStorage(Image::kImageRepCocoaTouch)) {