drive: Trigger "fast fetch" if remote update came during full loading.

chrome/browser/chromeos/drive/change_list_loader.cc

Index: chrome/browser/chromeos/drive/change_list_loader.cc
diff --git a/chrome/browser/chromeos/drive/change_list_loader.cc b/chrome/browser/chromeos/drive/change_list_loader.cc
index 5ecd19e7db2b19f00ecce0bced2c017fa7d733a6..7919c3c25ab8fcb13149641839334b57498f56d7 100644
--- a/chrome/browser/chromeos/drive/change_list_loader.cc
+++ b/chrome/browser/chromeos/drive/change_list_loader.cc
@@ -327,6 +327,15 @@ void ChangeListLoader::CheckForUpdates(const FileOperationCallback& callback) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(!callback.is_null());
 
+  // If the metadata is not yet loaded, CheckForUpdates does nothing.
+  if (!loaded_ && !IsRefreshing())
+    return;
+
+  // For each CheckForUpdates() request, always refresh the changestamp info.
+  about_resource_loader_->UpdateAboutResource(
+      base::Bind(&ChangeListLoader::OnAboutResourceUpdated,
+                 weak_ptr_factory_.GetWeakPtr()));
+
   if (IsRefreshing()) {
     // There is in-flight loading. So keep the callback here, and check for
     // updates when the in-flight loading is completed.
@@ -348,8 +357,12 @@ void ChangeListLoader::LoadIfNeeded(const FileOperationCallback& callback) {
   DCHECK(!callback.is_null());
 
   // If the metadata is not yet loaded, start loading.
-  if (!loaded_)
+  if (!loaded_ && !IsRefreshing()) {
+    about_resource_loader_->UpdateAboutResource(

[hashimoto, 2014/08/06 05:55:43]

GetAboutResource() requests the resource if not available.
Why should we call UpdateAboutResource() here?

[kinaba, 2014/08/06 06:16:54]

Good point. Done.

+        base::Bind(&ChangeListLoader::OnAboutResourceUpdated,
+                   weak_ptr_factory_.GetWeakPtr()));
     Load(callback);
+  }
 }
 
 void ChangeListLoader::Load(const FileOperationCallback& callback) {
@@ -402,7 +415,7 @@ void ChangeListLoader::LoadAfterGetLargestChangestamp(
         base::Bind(&util::EmptyFileOperationCallback));
   }
 
-  about_resource_loader_->UpdateAboutResource(
+  about_resource_loader_->GetAboutResource(
       base::Bind(&ChangeListLoader::LoadAfterGetAboutResource,
                  weak_ptr_factory_.GetWeakPtr(),
                  *local_changestamp));
@@ -463,6 +476,22 @@ void ChangeListLoader::OnChangeListLoadComplete(FileError error) {
   }
 }
 
+void ChangeListLoader::OnAboutResourceUpdated(
+    google_apis::GDataErrorCode error,
+    scoped_ptr<google_apis::AboutResource> resource) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  if (drive::GDataToFileError(error) != drive::FILE_ERROR_OK) {
+    logger_->Log(logging::LOG_ERROR,
+                 "Failed to update the about resource: %s",
+                 google_apis::GDataErrorCodeToString(error).c_str());
+    return;
+  }
+  logger_->Log(logging::LOG_INFO,
+               "About resource updated to: %s",
+               base::Int64ToString(resource->largest_change_id()).c_str());
+}
+
 void ChangeListLoader::LoadChangeListFromServer(int64 start_changestamp) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(!change_feed_fetcher_);