Add request header on gdata operation for testing ETag match.

chrome/browser/google_apis/gdata_operations.h

Index: chrome/browser/google_apis/gdata_operations.h
diff --git a/chrome/browser/google_apis/gdata_operations.h b/chrome/browser/google_apis/gdata_operations.h
index af3262ee442560926c827b1a180ecb3673e8a3db..46eacacb6cef3bd698d76258a64ef24a25cd0ed6 100644
--- a/chrome/browser/google_apis/gdata_operations.h
+++ b/chrome/browser/google_apis/gdata_operations.h
@@ -97,13 +97,22 @@ typedef base::Callback<void(GDataErrorCode error,
 // This class performs the operation for downloading of a given document/file.
 class DownloadFileOperation : public UrlFetchOperationBase {
  public:
+  // Downloads a file identified by its |document_url|.
+  // If |etag| is set, checks if it matches the file before downloading.

[satorux1, 2012/10/17 03:14:27]

If etag does not match, what happens? Please document.

+  // The downloaded file will be stored at |output_file_path| location.
+  // On partial data is received, invokes |get_content_callbac| if not empty.
+  // Upon completion, invokes |download_action_callback|.

[satorux1, 2012/10/17 03:14:27]

Thank you for improving the comment here!

+  //
+  // Registers the download task to |registry| with OperationProgressStatus
+  // associated with |virtual_path|.
   DownloadFileOperation(
       OperationRegistry* registry,
       const DownloadActionCallback& download_action_callback,
       const GetContentCallback& get_content_callback,
       const GURL& document_url,
       const FilePath& virtual_path,
-      const FilePath& output_file_path);
+      const FilePath& output_file_path,
+      const std::string& etag);
   virtual ~DownloadFileOperation();
 
  protected:
@@ -111,6 +120,7 @@ class DownloadFileOperation : public UrlFetchOperationBase {
   virtual GURL GetURL() const OVERRIDE;
   virtual void ProcessURLFetchResults(const net::URLFetcher* source) OVERRIDE;
   virtual void RunCallbackOnPrematureFailure(GDataErrorCode code) OVERRIDE;
+  virtual std::vector<std::string> GetExtraRequestHeaders() const OVERRIDE;
 
   // Overridden from net::URLFetcherDelegate.
   virtual void OnURLFetchDownloadProgress(const net::URLFetcher* source,
@@ -124,6 +134,7 @@ class DownloadFileOperation : public UrlFetchOperationBase {
   DownloadActionCallback download_action_callback_;
   GetContentCallback get_content_callback_;
   GURL document_url_;
+  std::string etag_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadFileOperation);
 };
@@ -133,9 +144,15 @@ class DownloadFileOperation : public UrlFetchOperationBase {
 // This class performs the operation for deleting a document.
 class DeleteDocumentOperation : public EntryActionOperation {
  public:
+  // Deletes a file identified by its |document_url|.
+  // If |etag| is set, checks if it matches the file before deletion.

[satorux1, 2012/10/17 03:14:27]

If etag does not match, what happens? Please document.

+  // Upon completion, invokes |callback|.
+  //
+  // Registers the download task to |registry|.
   DeleteDocumentOperation(OperationRegistry* registry,
                           const EntryActionCallback& callback,
-                          const GURL& document_url);
+                          const GURL& document_url,
+                          const std::string& etag);
   virtual ~DeleteDocumentOperation();
 
  protected:
@@ -147,6 +164,8 @@ class DeleteDocumentOperation : public EntryActionOperation {
   virtual std::vector<std::string> GetExtraRequestHeaders() const OVERRIDE;
 
  private:
+  std::string etag_;
+
   DISALLOW_COPY_AND_ASSIGN(DeleteDocumentOperation);
 };
 
@@ -327,17 +346,20 @@ class RemoveResourceFromDirectoryOperation : public EntryActionOperation {
 // When uploading a new file (UPLOAD_NEW_FILE):
 // - |title| should be set.
 // - |upload_location| should be the upload_url() of the parent directory.
+// - |etag| should be empty.
 //
 // When updating an existing file (UPLOAD_EXISTING_FILE):
-// - |title| should be empty
+// - |title| should be empty.
 // - |upload_location| should be the upload_url() of the existing file.
+// - |etag| should match the existing file. If it's empty, matching is skipped.

[satorux1, 2012/10/17 03:14:27]

If etag does not match, what happens? Please document.

 struct InitiateUploadParams {
   InitiateUploadParams(UploadMode upload_mode,
                        const std::string& title,
                        const std::string& content_type,
                        int64 content_length,
                        const GURL& upload_location,
-                       const FilePath& virtual_path);
+                       const FilePath& virtual_path,
+                       const std::string& etag);
   ~InitiateUploadParams();
 
   UploadMode upload_mode;
@@ -346,6 +368,7 @@ struct InitiateUploadParams {
   int64 content_length;
   GURL upload_location;
   FilePath virtual_path;
+  std::string etag;
 };
 
 // Callback type for DocumentServiceInterface::InitiateUpload.
@@ -406,7 +429,8 @@ struct ResumeUploadParams {
                      const std::string& content_type,
                      scoped_refptr<net::IOBuffer> buf,
                      const GURL& upload_location,
-                     const FilePath& virtual_path);
+                     const FilePath& virtual_path,
+                     const std::string& etag);
   ~ResumeUploadParams();
 
   UploadMode upload_mode;  // Mode of the upload.
@@ -419,6 +443,8 @@ struct ResumeUploadParams {
   // Virtual GData path of the file seen in the UI. Not necessary for
   // resuming an upload, but used for adding an entry to OperationRegistry.
   FilePath virtual_path;
+  // ETag matches the file to be overwritten. Matching is skipped if it's empty.
+  std::string etag;
 };
 
 // Callback type for DocumentServiceInterface::ResumeUpload.