WebUI: Move {Resolve|Reject}JavascriptCallback helpers in WebUIMessageHandler.

cr.sendWithPromise() is gaining traction outside of MD Settings, and the
C++ helpers to resolve/reject a JS Promise are more useful in the
superclass WebUIMessageHandler instead of SettingsPageUIHandler.

Review-Url: https://codereview.chromium.org/2040473002
Cr-Commit-Position: refs/heads/master@{#398166}

chrome/browser/ui/webui/settings/settings_page_ui_handler.cc

@@ -12,20 +12,4 @@ SettingsPageUIHandler::SettingsPageUIHandler() {}
 
 SettingsPageUIHandler::~SettingsPageUIHandler() {}
 
-void SettingsPageUIHandler::ResolveJavascriptCallback(
-    const base::Value& callback_id,
-    const base::Value& response) {
-  // cr.webUIResponse is a global JS function exposed from cr.js.
-  CallJavascriptFunction("cr.webUIResponse", callback_id,
-                         base::FundamentalValue(true), response);
-}
-
-void SettingsPageUIHandler::RejectJavascriptCallback(
-    const base::Value& callback_id,
-    const base::Value& response) {
-  // cr.webUIResponse is a global JS function exposed from cr.js.
-  CallJavascriptFunction("cr.webUIResponse", callback_id,
-                         base::FundamentalValue(false), response);
-}
-
 }  // namespace settings

chrome/browser/ui/webui/settings/settings_page_ui_handler.h

@@ -17,19 +17,6 @@ class SettingsPageUIHandler : public content::WebUIMessageHandler {
   SettingsPageUIHandler();
   ~SettingsPageUIHandler() override;
 
- protected:
-  // Helper method for responding to JS requests initiated with
-  // cr.sendWithPromise(), for the case where the returned promise should be
-  // resolved (request succeeded).
-  void ResolveJavascriptCallback(const base::Value& callback_id,
-                                 const base::Value& response);
-
-  // Helper method for responding to JS requests initiated with
-  // cr.sendWithPromise(), for the case where the returned promise should be
-  // rejected (request failed).
-  void RejectJavascriptCallback(const base::Value& callback_id,
-                                const base::Value& response);
-
  private:
   // SettingsPageUIHandler subclasses must be JavaScript-lifecycle safe.
   void OnJavascriptAllowed() override = 0;

chrome/browser/ui/webui/signin/signin_supervised_user_import_handler.cc

@@ -81,6 +81,7 @@ void SigninSupervisedUserImportHandler::AssignWebUICallbackId(
   CHECK_LE(1U, args->GetSize());
   CHECK(webui_callback_id_.empty());
   CHECK(args->GetString(0, &webui_callback_id_));
+  AllowJavascript();
 }
 
 void SigninSupervisedUserImportHandler::OpenUrlInLastActiveProfileBrowser(
@@ -190,9 +191,9 @@ void SigninSupervisedUserImportHandler::LoadCustodianProfileCallback(
 
 void SigninSupervisedUserImportHandler::RejectCallback(
     const base::string16& error) {
-  web_ui()->CallJavascriptFunctionUnsafe(
-      "cr.webUIResponse", base::StringValue(webui_callback_id_),
-      base::FundamentalValue(false), base::StringValue(error));
+  RejectJavascriptCallback(
+      base::StringValue(webui_callback_id_),
+      base::StringValue(error));
   webui_callback_id_.clear();
 }
 
@@ -266,9 +267,9 @@ void SigninSupervisedUserImportHandler::SendExistingSupervisedUsers(
   }
 
   // Resolve callback with response.
-  web_ui()->CallJavascriptFunctionUnsafe(
-      "cr.webUIResponse", base::StringValue(webui_callback_id_),
-      base::FundamentalValue(true), supervised_users);
+  ResolveJavascriptCallback(
+      base::StringValue(webui_callback_id_),
+      supervised_users);
   webui_callback_id_.clear();
 }
 

chrome/browser/ui/webui/signin/user_manager_screen_handler.cc

@@ -502,9 +502,9 @@ void UserManagerScreenHandler::HandleAreAllProfilesLocked(
   bool success = args->GetString(0, &webui_callback_id);
   DCHECK(success);
 
-  web_ui()->CallJavascriptFunctionUnsafe(
-      "cr.webUIResponse", base::StringValue(webui_callback_id),
-      base::FundamentalValue(true),
+  AllowJavascript();
+  ResolveJavascriptCallback(
+      base::StringValue(webui_callback_id),
       base::FundamentalValue(profiles::AreAllProfilesLocked()));
 }
 

content/browser/webui/web_ui_message_handler.cc

@@ -73,4 +73,20 @@ void WebUIMessageHandler::RenderViewReused() {
   DisallowJavascript();
 }
 
+void WebUIMessageHandler::ResolveJavascriptCallback(
+    const base::Value& callback_id,
+    const base::Value& response) {
+  // cr.webUIResponse is a global JS function exposed from cr.js.
+  CallJavascriptFunction("cr.webUIResponse", callback_id,
+                         base::FundamentalValue(true), response);
+}
+
+void WebUIMessageHandler::RejectJavascriptCallback(
+    const base::Value& callback_id,
+    const base::Value& response) {
+  // cr.webUIResponse is a global JS function exposed from cr.js.
+  CallJavascriptFunction("cr.webUIResponse", callback_id,
+                         base::FundamentalValue(false), response);
+}
+
 }  // namespace content

content/public/browser/web_ui_message_handler.h

@@ -77,6 +77,18 @@ class CONTENT_EXPORT WebUIMessageHandler {
   // to deregister or disabled observers that push JavaScript calls to the page.
   virtual void OnJavascriptDisallowed() {}
 
+  // Helper method for responding to Javascript requests initiated with
+  // cr.sendWithPromise() (defined in cr.js) for the case where the returned
+  // promise should be resolved (request succeeded).
+  void ResolveJavascriptCallback(const base::Value& callback_id,
+                                 const base::Value& response);
+
+  // Helper method for responding to Javascript requests initiated with
+  // cr.sendWithPromise() (defined in cr.js), for the case where the returned
+  // promise should be rejected (request failed).
+  void RejectJavascriptCallback(const base::Value& callback_id,
+                                const base::Value& response);
+
   // Call a Javascript function by sending its name and arguments down to
   // the renderer.  This is asynchronous; there's no way to get the result
   // of the call, and should be thought of more like sending a message to