Add IsDriveV2Enabled() utility function in gdata::util

chrome/browser/chromeos/gdata/gdata_util.h

Index: chrome/browser/chromeos/gdata/gdata_util.h
diff --git a/chrome/browser/chromeos/gdata/gdata_util.h b/chrome/browser/chromeos/gdata/gdata_util.h
index 62133c588e8530c922f650fa8a75597eb57d7154..8adb40235ce23fb33a31e9ef95afc4cf1c88c743 100644
--- a/chrome/browser/chromeos/gdata/gdata_util.h
+++ b/chrome/browser/chromeos/gdata/gdata_util.h
@@ -93,6 +93,10 @@ void ParseCacheFilePath(const FilePath& path,
                         std::string* resource_id,
                         std::string* md5,
                         std::string* extra_extension);
+
+// Returns true if Drive v2 API is enabled via commandline switch.
+bool IsDriveV2ApiEnabled();
+
 }  // namespace util
 }  // namespace gdata