Relanding the following revisions....

webkit/tools/test_shell/plugin_tests.cc

Index: webkit/tools/test_shell/plugin_tests.cc
===================================================================
--- webkit/tools/test_shell/plugin_tests.cc	(revision 13602)
+++ webkit/tools/test_shell/plugin_tests.cc	(working copy)
@@ -95,3 +95,31 @@
 
   DeleteTestPlugin();
 }
+
+TEST_F(PluginTest, DefaultPluginLoadTest) {
+  std::string html = "\
+      <div id='result'>Test running....</div>\
+      <script>\
+      function onSuccess() {\
+        var result = document.getElementById('result');\
+        result.innerHTML = 'DONE';\
+      }\
+      </script>\
+      <DIV ID=PluginDiv>\
+      <object classid=\"clsid:9E8BC6CE-AF35-400c-ABF6-A3F746A1871D\">\
+      <embed type=\"application/chromium-test-default-plugin\"\
+        mode=\"np_embed\"\
+      ></embed>\
+      </object>\
+      </DIV>\
+      ";
+
+  test_shell_->webView()->GetMainFrame()->LoadHTMLString(
+      html, GURL("about:blank"));
+  test_shell_->WaitTestFinished();
+
+  std::wstring text;
+  test_shell_->webView()->GetMainFrame()->GetContentAsPlainText(10000, &text);
+
+  ASSERT_EQ(true, StartsWith(text, L"DONE", true));
+}