Make image_decoder a Leaky LazyInstance

chrome/browser/bitmap_fetcher/bitmap_batch_fetcher.cc

+// Copyright 2015 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 "chrome/browser/bitmap_fetcher/bitmap_batch_fetcher.h"
+
+#include "content/public/browser/browser_thread.h"
+#include "net/url_request/url_fetcher.h"
+#include "net/url_request/url_request_context_getter.h"
+#include "net/url_request/url_request_status.h"
+
+namespace chrome {
+
+BitmapBatchFetcher::BitmapBatchFetcher() {
+  image_batch_decoder_ =
+      new ImageBatchDecoder(
+          content::BrowserThread::GetMessageLoopProxyForThread(
+              content::BrowserThread::UI));
+}
+
+BitmapBatchFetcher::~BitmapBatchFetcher() {
+}
+
+void BitmapBatchFetcher::Start(net::URLRequestContextGetter* request_context,
+                          const std::string& referrer,
+                          net::URLRequest::ReferrerPolicy referrer_policy,
+                          int load_flags,
+                          const GURL& url,
+                          BitmapFetcherDelegate* delegate) {
+  net::URLFetcher* url_fetcher =
+      net::URLFetcher::Create(url, net::URLFetcher::GET, this);
+  url_fetcher_map_[url_fetcher] =
+      std::pair<GURL, BitmapFetcherDelegate*>(url, delegate);
+
+  url_fetcher->SetRequestContext(request_context);
+  url_fetcher->SetReferrer(referrer);
+  url_fetcher->SetReferrerPolicy(referrer_policy);
+  url_fetcher->SetLoadFlags(load_flags);
+  url_fetcher->Start();
+}
+
+// Methods inherited from URLFetcherDelegate.
+
+void BitmapBatchFetcher::OnURLFetchComplete(const net::URLFetcher* source) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+
+  if (source->GetStatus().status() != net::URLRequestStatus::SUCCESS) {
+    url_fetcher_map_[source].second->OnFetchComplete(
+        url_fetcher_map_[source].first, NULL);
+    return;
+  }
+
+  std::string image_data;
+  source->GetResponseAsString(&image_data);
+  // Call start to begin decoding.  The ImageBatchDecoder will call
+  // OnImageDecoded with the data when it is done.
+  scoped_refptr<base::MessageLoopProxy> task_runner =
+      content::BrowserThread::GetMessageLoopProxyForThread(
+          content::BrowserThread::UI);
+  image_batch_decoder_->Start(
+      new BitmapBatchFetcher::Delegate(url_fetcher_map_[source].first,
+                                       url_fetcher_map_[source].second),
+      image_data,
+      ImageBatchDecoder::DEFAULT_CODEC);
+}
+
+void BitmapBatchFetcher::OnURLFetchDownloadProgress(
+    const net::URLFetcher* source,
+    int64 current,
+    int64 total) {
+  // Do nothing here.
+}
+
+// Methods inherited from ImageBatchDecoder::Delegate.
+
+void BitmapBatchFetcher::Delegate::OnImageDecoded(
+    const ImageBatchDecoder* decoder,
+    const SkBitmap& decoded_image) {
+  // Report success.
+  delegate_->OnFetchComplete(url_, &decoded_image);
+}
+
+void BitmapBatchFetcher::Delegate::OnDecodeImageFailed(
+    const ImageBatchDecoder* decoder) {
+  delegate_->OnFetchComplete(url_, NULL);
+}
+
+}  // namespace chrome