Relanding the following revisions....

webkit/default_plugin/plugin_main.cc

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "webkit/default_plugin/plugin_main.h"
 
 #include "base/logging.h"
+#include "base/string_util.h"
 #include "webkit/activex_shim/npp_impl.h"
 #include "webkit/default_plugin/plugin_impl.h"
 #include "webkit/glue/webkit_glue.h"
 
 namespace default_plugin {
 //
 // Forward declare the linker-provided pseudo variable for the
 // current module handle.
 //
 extern "C" IMAGE_DOS_HEADER __ImageBase;
@@ skipping 29 matching lines @@
   g_browser = funcs;
   activex_shim::g_browser = funcs;
   return 0;
 }
 
 NPError API_CALL NP_Shutdown(void) {
   g_browser = NULL;
   return 0;
 }
 
+namespace {
+// This function is only invoked when the default plugin is invoked
+// with a special mime type application/chromium-test-default-plugin
+void SignalTestResult(NPP instance) {
+  NPObject *window_obj = NULL;
+  g_browser->getvalue(instance, NPNVWindowNPObject, &window_obj);
+  if (!window_obj) {
+    NOTREACHED();
+    return;
+  }
+
+  std::string script = "javascript:onSuccess()";
+  NPString script_string;
+  script_string.UTF8Characters = script.c_str();
+  script_string.UTF8Length =
+      static_cast<unsigned int>(script.length());
+
+  NPVariant result_var;
+  NPError result = g_browser->evaluate(instance, window_obj,
+                                       &script_string, &result_var);
+  g_browser->releaseobject(window_obj);
+}
+
+}  // namespace CHROMIUM_DefaultPluginTest
+
 NPError NPP_New(NPMIMEType plugin_type, NPP instance, uint16 mode, int16 argc,
                 char* argn[], char* argv[], NPSavedData* saved) {
   if (instance == NULL)
     return NPERR_INVALID_INSTANCE_ERROR;
 
   // We don't want the null plugin to work in the following cases:-
   // 1. Test-shell
   // 2. The plugin is running in the renderer process.
   if (webkit_glue::IsPluginRunningInRendererProcess()) {
+    if (!base::strcasecmp(plugin_type,
+        "application/chromium-test-default-plugin")) {
+      SignalTestResult(instance);
+      return NPERR_NO_ERROR;
+    }
     return NPERR_GENERIC_ERROR;
   }
 
+
   PluginInstallerImpl* plugin_impl = new PluginInstallerImpl(mode);
   plugin_impl->Initialize(GetCurrentModuleHandle(), instance, plugin_type, argc,
                           argn, argv);
   instance->pdata = reinterpret_cast<void*>(plugin_impl);
   return NPERR_NO_ERROR;
 }
 
 NPError NPP_Destroy(NPP instance, NPSavedData** save) {
   PluginInstallerImpl* plugin_impl =
     reinterpret_cast<PluginInstallerImpl*>(instance->pdata);
@@ skipping 124 matching lines @@
   if (instance == NULL)
     return 0;
 
   PluginInstallerImpl* plugin_impl =
       reinterpret_cast<PluginInstallerImpl*>(instance->pdata);
 
   return plugin_impl->NPP_HandleEvent(event);
 }
 
 }   // default_plugin