Protect WebViewImpl::handleGestureEvent from null client

Source/web/tests/WebViewTest.cpp

Index: Source/web/tests/WebViewTest.cpp
diff --git a/Source/web/tests/WebViewTest.cpp b/Source/web/tests/WebViewTest.cpp
index e2caa90d24b416af5dd7d05e4aac2a9c8bf5c609..fe3cc0cb6a3be2062b6f614a2fb81408fa1d1c19 100644
--- a/Source/web/tests/WebViewTest.cpp
+++ b/Source/web/tests/WebViewTest.cpp
@@ -1274,6 +1274,18 @@ TEST_F(WebViewTest, ClientTapHandling)
     m_webViewHelper.reset(); // Explicitly reset to break dependency on locally scoped client.
 }
 
+TEST_F(WebViewTest, ClientTapHandlingClosedWindow)
+{
+    WebViewImpl* webView = WebViewImpl::create(nullptr);
+    webView->setMainFrame(WebLocalFrame::create(nullptr));
+    WebGestureEvent event;
+    event.type = WebInputEvent::GestureTap;
+    event.x = 3;
+    event.y = 8;
+    webView->handleInputEvent(event);
+    webView->close();

[aelias_OOO_until_Jul13, 2015/03/08 20:37:13]

Given that the close() is after the handleInputEvent() call, it doesn't seem
like this test gives us any coverage?  Does it really crash without the
WebViewImpl change?

+}
+
 #if OS(ANDROID)
 TEST_F(WebViewTest, LongPressSelection)
 {