Decode ImageManager cached images on demand.

components/suggestions/image_encoder_ios.mm

 // Copyright 2014 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 "components/suggestions/image_encoder.h"
 
 #import <UIKit/UIKit.h>
 
 #include "base/mac/scoped_cftyperef.h"
 #include "skia/ext/skia_utils_ios.h"
 
 namespace suggestions {
 
-SkBitmap* DecodeJPEGToSkBitmap(const std::vector<unsigned char>& encoded_data) {
-  NSData* data =
-      [NSData dataWithBytes:encoded_data.data() length:encoded_data.size()];
-  UIImage* image =
-     [UIImage imageWithData:data scale:1.0];
+SkBitmap* DecodeJPEGToSkBitmap(const void* encoded_data, size_t size) {
+  NSData* data = [NSData dataWithBytes:encoded_data length:size];
+  UIImage* image = [UIImage imageWithData:data scale:1.0];
   return new SkBitmap(gfx::CGImageToSkBitmap(image.CGImage, [image size], YES));
 }
 
 bool EncodeSkBitmapToJPEG(const SkBitmap& bitmap,
                           std::vector<unsigned char>* dest) {
   base::ScopedCFTypeRef<CGColorSpaceRef> color_space(
       CGColorSpaceCreateDeviceRGB());
   UIImage* image =
       gfx::SkBitmapToUIImageWithColorSpace(bitmap, 1 /* scale */, color_space);
   NSData* data = UIImageJPEGRepresentation(image, 1.0);
   const char* bytes = reinterpret_cast<const char*>([data bytes]);
   dest->assign(bytes, bytes + [data length]);
   return true;
 }
 
 }  // namespace suggestions