Stop setting invalid value to the |tab_id| field of fileBrowserHandler API.

chrome/browser/chromeos/extensions/file_manager/private_api_util.h

Index: chrome/browser/chromeos/extensions/file_manager/private_api_util.h
diff --git a/chrome/browser/chromeos/extensions/file_manager/private_api_util.h b/chrome/browser/chromeos/extensions/file_manager/private_api_util.h
index b8daae659dd5a066b30e8ee82a7ff895c6b4c95d..5f94aba4cdc827cd9c0c6f12eb651c8bda1d073c 100644
--- a/chrome/browser/chromeos/extensions/file_manager/private_api_util.h
+++ b/chrome/browser/chromeos/extensions/file_manager/private_api_util.h
@@ -48,10 +48,6 @@ void VolumeInfoToVolumeMetadata(
 // NULL on error.
 content::WebContents* GetWebContents(ExtensionFunctionDispatcher* dispatcher);
 
-// Returns the ID of the tab associated with the dispatcher. Returns 0 on
-// error.
-int32 GetTabId(ExtensionFunctionDispatcher* dispatcher);
-
 // Returns the local FilePath associated with |url|. If the file isn't of the
 // type FileSystemBackend handles, returns an empty
 // FilePath. |render_view_host| and |profile| are needed to obtain the