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 2be8f65d1cc9b355d8d43fbc14abcf2cd004a599..774525a46351530c710e1039eb21be0fb5263088 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;
+
 //================================ AuthOperation ===============================
 
 // OAuth2 authorization token retrieval operation.
@@ -112,7 +115,9 @@ 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
@@ -130,6 +135,9 @@ 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;
 
@@ -147,6 +155,9 @@ class UrlFetchOperationBase : public GDataOperationInterface,
   FilePath output_file_path_;
   scoped_ptr<net::URLFetcher> url_fetcher_;
   bool started_;
+
+ private:
+  base::WeakPtrFactory<UrlFetchOperationBase> weak_ptr_factory_;
 };
 
 //============================ EntryActionOperation ============================
@@ -163,7 +174,9 @@ 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_; }
@@ -186,15 +199,24 @@ 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);
 };