Make image_decoder a Leaky LazyInstance

chrome/browser/android/logo_service.cc

Index: chrome/browser/android/logo_service.cc
diff --git a/chrome/browser/android/logo_service.cc b/chrome/browser/android/logo_service.cc
index ddcb626361050d372542a332ab237ab94479e4ed..c40d3906666ce0a6e308f341cdcf9d88880f042a 100644
--- a/chrome/browser/android/logo_service.cc
+++ b/chrome/browser/android/logo_service.cc
@@ -39,38 +39,34 @@ GURL GetGoogleDoodleURL(Profile* profile) {
 class LogoDecoderDelegate : public ImageDecoder::Delegate {
  public:
   LogoDecoderDelegate(
-      const scoped_refptr<ImageDecoder>& image_decoder,
       const base::Callback<void(const SkBitmap&)>& image_decoded_callback)
-      : image_decoder_(image_decoder),
-        image_decoded_callback_(image_decoded_callback),
+      : image_decoded_callback_(image_decoded_callback),
         weak_ptr_factory_(this) {
     // If the ImageDecoder crashes or otherwise never completes, call
     // OnImageDecodeTimedOut() eventually to ensure that image_decoded_callback_
     // is run.
     base::MessageLoopProxy::current()->PostDelayedTask(
-        FROM_HERE,
-        base::Bind(&LogoDecoderDelegate::OnDecodeImageFailed,
-                   weak_ptr_factory_.GetWeakPtr(),
-                   (const ImageDecoder*) NULL),
+        FROM_HERE, base::Bind(&LogoDecoderDelegate::OnDecodeImageFailed,
+                              weak_ptr_factory_.GetWeakPtr()),
         base::TimeDelta::FromSeconds(kDecodeLogoTimeoutSeconds));
   }
 
-  ~LogoDecoderDelegate() override { image_decoder_->set_delegate(NULL); }
+  ~LogoDecoderDelegate() override {
+    ImageDecoder::GetInstance()->RemoveDelegate(this);

[dcheng, 2015/03/19 14:25:46]

I don't know that having GetInstance() everywhere is particularly helpful.

To my knowledge, ImageDecoder isn't mocked out in tests. So we could just make
Start()/RemoveDelegate() static methods and save a bunch of typing. WDYT?

[Theresa, 2015/03/19 21:54:56]

Done. I agree, it's not particularly helpful to expose GetInstance().

+  }
 
   // ImageDecoder::Delegate:
-  void OnImageDecoded(const ImageDecoder* decoder,
-                      const SkBitmap& decoded_image) override {
+  void OnImageDecoded(const SkBitmap& decoded_image) override {
     image_decoded_callback_.Run(decoded_image);
     delete this;
   }
 
-  void OnDecodeImageFailed(const ImageDecoder* decoder) override {
+  void OnDecodeImageFailed() override {
     image_decoded_callback_.Run(SkBitmap());
     delete this;
   }
 
  private:
-  scoped_refptr<ImageDecoder> image_decoder_;
   base::Callback<void(const SkBitmap&)> image_decoded_callback_;
   base::WeakPtrFactory<LogoDecoderDelegate> weak_ptr_factory_;
 
@@ -86,14 +82,11 @@ class ChromeLogoDelegate : public search_provider_logos::LogoDelegate {
   void DecodeUntrustedImage(
       const scoped_refptr<base::RefCountedString>& encoded_image,
       base::Callback<void(const SkBitmap&)> image_decoded_callback) override {
-    scoped_refptr<ImageDecoder> image_decoder = new ImageDecoder(
-        NULL,
-        encoded_image->data(),
-        ImageDecoder::DEFAULT_CODEC);
     LogoDecoderDelegate* delegate =
-        new LogoDecoderDelegate(image_decoder, image_decoded_callback);
-    image_decoder->set_delegate(delegate);
-    image_decoder->Start(base::MessageLoopProxy::current());
+        new LogoDecoderDelegate(image_decoded_callback);
+    ImageDecoder::GetInstance()->Start(
+        delegate, encoded_image->data(), ImageDecoder::DEFAULT_CODEC,
+        base::MessageLoopProxy::current(), false);
   }
 
  private: