gdrive: Get JSON feeds parsing off the UI thread.

chrome/browser/chromeos/gdata/operations_base.h

Index: chrome/browser/chromeos/gdata/operations_base.h
diff --git a/chrome/browser/chromeos/gdata/operations_base.h b/chrome/browser/chromeos/gdata/operations_base.h
index cf8ee2c78eda275d794106450fff89f24c057c60..3cb5898abb775f7b3f3a0e81079e38ad73d655a0 100644
--- a/chrome/browser/chromeos/gdata/operations_base.h
+++ b/chrome/browser/chromeos/gdata/operations_base.h
@@ -20,6 +20,9 @@ class OAuth2AccessTokenFetcher;
 
 namespace gdata {
 
+// Callback type for ProcessURLFetchResults.
+typedef base::Callback<void(bool result)> ProcessURLFetchResultsCallBack;

[hashimoto, 2012/07/20 04:07:37]

nit: s/CallBack/Callback/ We use 'callback' as one word.

BTW, do we need this typedef at all?
Why can't we call OnProcessURLFetchResultsComplete() directly?

[yoshiki, 2012/07/24 16:58:32]

Done
If we call OnProcessURLFetchResultsComplete() directly, we have to change it
public because it is called from OnDataParsed() in operations_base.cc. I think
passing callback is better than it.

[hashimoto, 2012/07/25 06:14:21]

How about making OnDataParsed() a private method of GetDataOperation?

Having two callbacks (|callback| and |result_callback|) as arguments of
OnDataParsed() is confusing.  It's good to avoid it if possible.

+
 //================================ AuthOperation ===============================
 
 // OAuth2 authorization token retrieval operation.
@@ -111,7 +114,9 @@ class UrlFetchOperationBase : public GDataOperationInterface,
 
   // Invoked by OnURLFetchComplete when the operation completes without an
   // authentication error. Must be implemented by a derived class.
-  virtual bool ProcessURLFetchResults(const net::URLFetcher* source) = 0;
+  virtual void ProcessURLFetchResults(
+      const net::URLFetcher* source,
+      const ProcessURLFetchResultsCallBack& callback) = 0;
 
   // Invoked when it needs to notify the status. Chunked operations that
   // constructs a logically single operation from multiple physical operations
@@ -129,6 +134,9 @@ class UrlFetchOperationBase : public GDataOperationInterface,
   // Overridden from URLFetcherDelegate.
   virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
 
+  // Invoked when ProcessURLFetchResults() is completed.
+  void OnProcessURLFetchResultsComplete(bool result);
+
   // Overridden from GDataOperationInterface.
   virtual void OnAuthFailed(GDataErrorCode code) OVERRIDE;
 
@@ -146,6 +154,7 @@ class UrlFetchOperationBase : public GDataOperationInterface,
   FilePath output_file_path_;
   scoped_ptr<net::URLFetcher> url_fetcher_;
   bool started_;
+  base::WeakPtrFactory<UrlFetchOperationBase> weak_ptr_factory_;

[hashimoto, 2012/07/20 04:07:37]

Can't this be private instead of protected?

[yoshiki, 2012/07/24 16:58:32]

Done.

 };
 
 //============================ EntryActionOperation ============================
@@ -162,7 +171,9 @@ class EntryActionOperation : public UrlFetchOperationBase {
 
  protected:
   // Overridden from UrlFetchOperationBase.
-  virtual bool ProcessURLFetchResults(const net::URLFetcher* source) OVERRIDE;
+  virtual void ProcessURLFetchResults(
+      const net::URLFetcher* source,
+      const ProcessURLFetchResultsCallBack& callback) OVERRIDE;
   virtual void RunCallbackOnPrematureFailure(GDataErrorCode code) OVERRIDE;
 
   const GURL& document_url() const { return document_url_; }
@@ -185,15 +196,24 @@ class GetDataOperation : public UrlFetchOperationBase {
   virtual ~GetDataOperation();
 
   // Parse GData JSON response.
-  virtual base::Value* ParseResponse(const std::string& data);
+  virtual void ParseResponse(
+      GDataErrorCode fetch_error_code,
+      const std::string& data,
+      const ProcessURLFetchResultsCallBack& result_callback);
 
  protected:
   // Overridden from UrlFetchOperationBase.
-  virtual bool ProcessURLFetchResults(const net::URLFetcher* source) OVERRIDE;
-  virtual void RunCallbackOnPrematureFailure(GDataErrorCode code) OVERRIDE;
+  virtual void ProcessURLFetchResults(
+      const net::URLFetcher* source,
+      const ProcessURLFetchResultsCallBack& callback) OVERRIDE;
+  virtual void RunCallbackOnPrematureFailure(
+      GDataErrorCode fetch_error_code) OVERRIDE;
+  void RunCallback(GDataErrorCode fetch_error_code,
+                   scoped_ptr<base::Value> value);
 
  private:
   GetDataCallback callback_;
+
   DISALLOW_COPY_AND_ASSIGN(GetDataOperation);
 };