Make image_decoder a Leaky LazyInstance

chrome/browser/extensions/webstore_install_helper.h

 // Copyright (c) 2012 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 CHROME_BROWSER_EXTENSIONS_WEBSTORE_INSTALL_HELPER_H_
 #define CHROME_BROWSER_EXTENSIONS_WEBSTORE_INSTALL_HELPER_H_
 
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
+#include "chrome/browser/image_decoder.h"
 #include "content/public/browser/utility_process_host_client.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "url/gurl.h"
 
 class SkBitmap;
 
 namespace base {
 class DictionaryValue;
 class ListValue;
 }
 
 namespace content {
 class UtilityProcessHost;
 }
 
 namespace net {
 class URLFetcher;
 class URLRequestContextGetter;
 }
 
 namespace extensions {
 
 // This is a class to help dealing with webstore-provided data. It manages
 // sending work to the utility process for parsing manifests and
 // fetching/decoding icon data. Clients must implement the
 // WebstoreInstallHelper::Delegate interface to receive the parsed data.
-class WebstoreInstallHelper : public content::UtilityProcessHostClient,
+class WebstoreInstallHelper : public ImageDecoder::Delegate,
+                              public content::UtilityProcessHostClient,
                               public net::URLFetcherDelegate {
  public:
   class Delegate {
    public:
     enum InstallHelperResultCode {
       UNKNOWN_ERROR,
       ICON_ERROR,
       MANIFEST_ERROR
     };
 
     // Called when we've successfully parsed the manifest and decoded the icon
     // in the utility process. Ownership of parsed_manifest is transferred.
     virtual void OnWebstoreParseSuccess(
         const std::string& id,
         const SkBitmap& icon,
         base::DictionaryValue* parsed_manifest) = 0;
 
     // Called to indicate a parse failure. The |result_code| parameter should
     // indicate whether the problem was with the manifest or icon.
     virtual void OnWebstoreParseFailure(
         const std::string& id,
         InstallHelperResultCode result_code,
         const std::string& error_message) = 0;
 
    protected:
     virtual ~Delegate() {}
   };
 
-  // Only one of |icon_data| (based64-encoded icon data) or |icon_url| can be
-  // specified, but it is legal for both to be empty.
+  // |icon_url| can be empty.

[asargent_no_longer_on_chrome, 2015/03/12 21:40:08]

pedantic nit: We might want this to be something like "It is legal for
|icon_url| to be empty.", or at a minimum change the word "can" to "may" to make
it clear that we are giving permission to consumers of the API to not provide an
icon URL here. 

[Theresa, 2015/03/12 22:19:10]

Done.

   WebstoreInstallHelper(Delegate* delegate,
                         const std::string& id,
                         const std::string& manifest,
-                        const std::string& icon_data,
                         const GURL& icon_url,
                         net::URLRequestContextGetter* context_getter);
   void Start();
 
  private:
   ~WebstoreInstallHelper() override;
 
   void StartWorkOnIOThread();
   void StartFetchedImageDecode();
   void ReportResultsIfComplete();
   void ReportResultFromUIThread();
 
   // Implementing the net::URLFetcherDelegate interface.
   void OnURLFetchComplete(const net::URLFetcher* source) override;
 
   // Implementing pieces of the UtilityProcessHostClient interface.
   bool OnMessageReceived(const IPC::Message& message) override;
 
   // Message handlers.
-  void OnDecodeImageSucceeded(const SkBitmap& decoded_image);
-  void OnDecodeImageFailed();
   void OnJSONParseSucceeded(const base::ListValue& wrapper);
   void OnJSONParseFailed(const std::string& error_message);
 
+  // ImageDecoder::Delegate implementation.
+  void OnImageDecoded(const SkBitmap& decoded_image) override;
+  void OnDecodeImageFailed() override;
+
   // The client who we'll report results back to.
   Delegate* delegate_;
 
   // The extension id of the manifest we're parsing.
   std::string id_;
 
   // The manifest to parse.
   std::string manifest_;
 
-  // Only one of these should be non-empty. If |icon_base64_data_| is non-emtpy,
-  // it's a base64-encoded string that needs to be parsed into an SkBitmap. If
-  // |icon_url_| is non-empty, it needs to be fetched and decoded into an
+  // If |icon_url_| is non-empty, it needs to be fetched and decoded into an
   // SkBitmap.
-  std::string icon_base64_data_;
   GURL icon_url_;
   std::vector<unsigned char> fetched_icon_data_;
 
   // For fetching the icon, if needed.
   scoped_ptr<net::URLFetcher> url_fetcher_;
   net::URLRequestContextGetter* context_getter_; // Only usable on UI thread.
 
   base::WeakPtr<content::UtilityProcessHost> utility_host_;
 
   // Flags for whether we're done doing icon decoding and manifest parsing.
   bool icon_decode_complete_;
   bool manifest_parse_complete_;
 
   // The results of succesful decoding/parsing.
   SkBitmap icon_;
   scoped_ptr<base::DictionaryValue> parsed_manifest_;
 
   // A details string for keeping track of any errors.
   std::string error_;
 
   // A code to distinguish between an error with the icon, and an error with the
   // manifest.
   Delegate::InstallHelperResultCode parse_error_;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_WEBSTORE_INSTALL_HELPER_H_