[FileBrowser] Added DefaultAction dialog to choose default action.

chrome/browser/chromeos/extensions/file_browser_private_api.cc

Index: chrome/browser/chromeos/extensions/file_browser_private_api.cc
diff --git a/chrome/browser/chromeos/extensions/file_browser_private_api.cc b/chrome/browser/chromeos/extensions/file_browser_private_api.cc
index 4f7bbe3cfc0c523fa82811c4357948a2ac3600aa..9f1b6375f06f533247a047bd3d6ebfd7d468df10 100644
--- a/chrome/browser/chromeos/extensions/file_browser_private_api.cc
+++ b/chrome/browser/chromeos/extensions/file_browser_private_api.cc
@@ -632,6 +632,26 @@ void ExecuteTasksFileBrowserFunction::OnTaskExecuted(bool success) {
   SendResponse(success);
 }
 
+SetDefaultTaskFileBrowserFunction::SetDefaultTaskFileBrowserFunction() {}
+
+SetDefaultTaskFileBrowserFunction::~SetDefaultTaskFileBrowserFunction() {}
+
+bool SetDefaultTaskFileBrowserFunction::RunImpl() {
+  // First param is task id that was to the extension with setDefaultTask call.
+  std::string task_id;
+  if (!args_->GetString(0, &task_id) || !task_id.size())
+    return false;
+
+  BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(
+            &file_handler_util::UpdateFileHandlerUsageStats,
+            profile_, task_id));
+
+  result_.reset(new base::FundamentalValue(true));
+  return true;
+}
+
 FileBrowserFunction::FileBrowserFunction() {
 }