Protect WebViewImpl::handleGestureEvent from null client

Source/web/tests/WebViewTest.cpp

 /*
  * Copyright (C) 2011, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 1256 matching lines @@
     event.x = 25;
     event.y = 7;
     webView->handleInputEvent(event);
     runPendingTasks();
     EXPECT_EQ(25, client.longpressX());
     EXPECT_EQ(7, client.longpressY());
 
     m_webViewHelper.reset(); // Explicitly reset to break dependency on locally scoped client.
 }
 
+TEST_F(WebViewTest, ClientTapHandlingNullWebViewClient)
+{
+    WebViewImpl* webView = WebViewImpl::create(nullptr);
+    webView->setMainFrame(WebLocalFrame::create(nullptr));
+    WebGestureEvent event;
+    event.type = WebInputEvent::GestureTap;
+    event.x = 3;
+    event.y = 8;
+    EXPECT_FALSE(webView->handleInputEvent(event));
+    webView->close();
+}
+
 #if OS(ANDROID)
 TEST_F(WebViewTest, LongPressSelection)
 {
     URLTestHelpers::registerMockedURLFromBaseURL(WebString::fromUTF8(m_baseURL.c_str()), WebString::fromUTF8("longpress_selection.html"));
 
     WebView* webView = m_webViewHelper.initializeAndLoad(m_baseURL + "longpress_selection.html", true);
     webView->resize(WebSize(500, 300));
     webView->layout();
     runPendingTasks();
 
@@ skipping 1167 matching lines @@
     // Test without any preventDefault.
     client.reset();
     frame->executeScript(WebScriptSource("setTest('none');"));
     EXPECT_TRUE(tapElementById(webView, WebInputEvent::GestureTap, WebString::fromUTF8("target")));
     EXPECT_TRUE(client.getWasCalled());
 
     m_webViewHelper.reset(); // Remove dependency on locally scoped client.
 }
 
 } // namespace