WebUI: Add JavaScript lifecycle-control to WebUIMessageHandler.

content/public/test/test_web_ui.cc

Index: content/public/test/test_web_ui.cc
diff --git a/content/public/test/test_web_ui.cc b/content/public/test/test_web_ui.cc
index 03c4d7bd376d02391af6bc14219c29db416475a7..a365219859903d66b6b3b26e62bcc4ff61be12a8 100644
--- a/content/public/test/test_web_ui.cc
+++ b/content/public/test/test_web_ui.cc
@@ -51,6 +51,10 @@ void TestWebUI::AddMessageHandler(WebUIMessageHandler* handler) {
   handlers_.push_back(handler);
 }
 
+bool TestWebUI::CanCallJavascript() {
+  return true;
+}
+
 void TestWebUI::CallJavascriptFunction(const std::string& function_name) {
   call_data_.push_back(new CallData(function_name));
 }