Do not open SELECT popup if the SELECT element is not in the viewport.

third_party/WebKit/Source/web/ExternalPopupMenuTest.cpp

Index: third_party/WebKit/Source/web/ExternalPopupMenuTest.cpp
diff --git a/third_party/WebKit/Source/web/ExternalPopupMenuTest.cpp b/third_party/WebKit/Source/web/ExternalPopupMenuTest.cpp
index 35aff82a5a19371a2a7d42e1f1ab71d4d9a89416..a0b5a4370baed599de7116f271b15d6c4c74a94c 100644
--- a/third_party/WebKit/Source/web/ExternalPopupMenuTest.cpp
+++ b/third_party/WebKit/Source/web/ExternalPopupMenuTest.cpp
@@ -120,6 +120,8 @@ protected:
     void loadFrame(const std::string& fileName)
     {
         FrameTestHelpers::loadFrame(mainFrame(), m_baseURL + fileName);
+        webView()->resize(WebSize(800, 600));
+        webView()->updateAllLifecyclePhases();
     }
 
     WebViewImpl* webView() const { return m_helper.webViewImpl(); }