Add ios_image_decoder_impl.* and pass an instance to the NTPSnippetsService...

Add ios_image_decoder_impl.* and pass an instance to the NTPSnippetsService when it is instantiated on iOS.

BUG=609127

Review-Url: https://codereview.chromium.org/2111573002
Cr-Commit-Position: refs/heads/master@{#403198}

components/image_fetcher/image_decoder.h

@@ -6,7 +6,9 @@
 #define COMPONENTS_IMAGE_FETCHER_IMAGE_DECODER_H_
 
 #include <string>
+
 #include "base/callback_forward.h"
+#include "base/macros.h"
 
 namespace gfx {
 class Image;

components/ntp_snippets/ntp_snippets_service.cc

@@ -586,7 +586,7 @@ void NTPSnippetsService::OnSnippetImageFetchedFromDatabase(
     const std::string& snippet_id,
     const ImageFetchedCallback& callback,
     std::string data) {
-  // |image_decoder_| is null on iOS and in tests.
+  // |image_decoder_| is null in tests.
   if (image_decoder_ && !data.empty()) {
     image_decoder_->DecodeImage(
         std::move(data),

ios/chrome/browser/BUILD.gn

@@ -408,6 +408,8 @@ source_set("browser") {
     "ssl/ios_ssl_blocking_page.mm",
     "suggestions/image_fetcher_impl.h",
     "suggestions/image_fetcher_impl.mm",
+    "suggestions/ios_image_decoder_impl.h",
+    "suggestions/ios_image_decoder_impl.mm",
     "suggestions/suggestions_service_factory.h",
     "suggestions/suggestions_service_factory.mm",
     "sync/glue/sync_start_util.cc",

ios/chrome/browser/ntp_snippets/ios_chrome_ntp_snippets_service_factory.cc

@@ -26,6 +26,7 @@
 #include "ios/chrome/browser/signin/oauth2_token_service_factory.h"
 #include "ios/chrome/browser/signin/signin_manager_factory.h"
 #include "ios/chrome/browser/suggestions/image_fetcher_impl.h"
+#include "ios/chrome/browser/suggestions/ios_image_decoder_impl.h"
 #include "ios/chrome/browser/suggestions/suggestions_service_factory.h"
 #include "ios/chrome/browser/sync/ios_chrome_profile_sync_service_factory.h"
 #include "ios/chrome/common/channel_info.h"
@@ -34,6 +35,7 @@
 #include "net/url_request/url_request_context_getter.h"
 
 using suggestions::ImageFetcherImpl;
+using suggestions::IOSImageDecoderImpl;
 using suggestions::SuggestionsService;
 using suggestions::SuggestionsServiceFactory;
 
@@ -122,7 +124,7 @@ IOSChromeNTPSnippetsServiceFactory::BuildServiceInstanceFor(
                      GetChannel() == version_info::Channel::STABLE)),
       base::WrapUnique(new ImageFetcherImpl(request_context.get(),
                                             web::WebThread::GetBlockingPool())),
-      nullptr, /* image_decoder */
+      base::MakeUnique<IOSImageDecoderImpl>(),
       base::WrapUnique(
           new ntp_snippets::NTPSnippetsDatabase(database_dir, task_runner)),
       base::WrapUnique(new ntp_snippets::NTPSnippetsStatusService(

ios/chrome/browser/suggestions/ios_image_decoder_impl.h

+// Copyright 2016 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.
+
+#ifndef IOS_CHROME_BROWSER_SUGGESTIONS_IOS_IMAGE_DECODER_IMPL_H_
+#define IOS_CHROME_BROWSER_SUGGESTIONS_IOS_IMAGE_DECODER_IMPL_H_
+
+#include "base/macros.h"
+#include "components/image_fetcher/image_decoder.h"
+
+namespace suggestions {
+
+class IOSImageDecoderImpl : public image_fetcher::ImageDecoder {
+ public:
+  IOSImageDecoderImpl();
+  ~IOSImageDecoderImpl() override;
+
+  void DecodeImage(
+      const std::string& image_data,
+      const image_fetcher::ImageDecodedCallback& callback) override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(IOSImageDecoderImpl);
+};
+
+}  // namespace suggestions
+
+#endif  // IOS_CHROME_BROWSER_SUGGESTIONS_IOS_IMAGE_DECODER_IMPL_H_

ios/chrome/browser/suggestions/ios_image_decoder_impl.mm

+// Copyright 2016 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 "ios/chrome/browser/suggestions/ios_image_decoder_impl.h"
+
+#include <UIKit/UIKit.h>
+
+#include "base/callback.h"
+#include "ui/gfx/image/image.h"
+
+namespace suggestions {
+
+IOSImageDecoderImpl::IOSImageDecoderImpl() {}
+
+IOSImageDecoderImpl::~IOSImageDecoderImpl() {}
+
+void IOSImageDecoderImpl::DecodeImage(
+    const std::string& image_data,
+    const image_fetcher::ImageDecodedCallback& callback) {
+  // Convert the |image_data| std::string to a NSData buffer.
+  NSData* data =
+      [NSData dataWithBytesNoCopy:const_cast<char*>(image_data.c_str())
+                           length:image_data.length()
+                     freeWhenDone:NO];
+
+  // Decode the Image using UIImage.
+  if (data) {
+    // Most likely always returns 1x images.
+    UIImage* ui_image = [UIImage imageWithData:data scale:1];
+    if (ui_image) {
+      gfx::Image gfx_image(ui_image);
+      callback.Run(gfx_image);
+      return;
+    }
+  }
+  gfx::Image empty_image;
+  callback.Run(empty_image);
+}
+
+}  // namespace suggestions

ios/chrome/ios_chrome.gyp

@@ -545,6 +545,8 @@
         'browser/ssl/ios_ssl_blocking_page.mm',
         'browser/suggestions/image_fetcher_impl.h',
         'browser/suggestions/image_fetcher_impl.mm',
+        'browser/suggestions/ios_image_decoder_impl.h',
+        'browser/suggestions/ios_image_decoder_impl.mm',
         'browser/suggestions/suggestions_service_factory.h',
         'browser/suggestions/suggestions_service_factory.mm',
         'browser/sync/glue/sync_start_util.cc',