Adding iOS support for image_store.

components/enhanced_bookmarks/image_store_util_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/enhanced_bookmarks/image_store_util.h"
+
+#import <UIKit/UIKit.h>
+
+#include "base/mac/scoped_cftyperef.h"
+#include "base/mac/scoped_nsobject.h"
+
+namespace {
+// An implementation of RefCountedMemory, where the bytes are stored in a
+// NSData. This class assumes the NSData is non mutable to avoid a copy.
+class RefCountedNSDataMemory : public base::RefCountedMemory {
+ public:
+  explicit RefCountedNSDataMemory(NSData* memory) : data_([memory retain]) {}
+
+  virtual const unsigned char* front() const OVERRIDE {
+    return reinterpret_cast<const unsigned char*>([data_ bytes]);
+  }
+
+  virtual size_t size() const OVERRIDE {
+    return [data_ length];
+  }
+
+private:
+  virtual ~RefCountedNSDataMemory() {}
+
+  base::scoped_nsobject<NSData> data_;
+  DISALLOW_COPY_AND_ASSIGN(RefCountedNSDataMemory);
+};
+}  // namespace
+
+namespace enhanced_bookmarks {
+
+// Encodes the UIImage representation of a gfx::Image.
+scoped_refptr<base::RefCountedMemory> BytesForImage(const gfx::Image& image) {
+  DCHECK(image.HasRepresentation(gfx::Image::kImageRepCocoaTouch));
+  return scoped_refptr<RefCountedNSDataMemory>(new RefCountedNSDataMemory(
+      [NSKeyedArchiver archivedDataWithRootObject:image.ToUIImage()]));
+}
+
+// Decodes the UIImage in the bytes and returns a gfx::Image.
+gfx::Image ImageForBytes(const scoped_refptr<base::RefCountedMemory>& data) {
+  return gfx::Image([[NSKeyedUnarchiver unarchiveObjectWithData:
+      [NSData dataWithBytes:data->front() length:data->size()]] retain]);
+}
+
+}  // namespace enhanced_bookmarks