Make it possible to enable/disable specific ppapi tests. Migrate PostMessage tests.

ppapi/tests/test_image_data.h

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
 
 #ifndef PPAPI_TESTS_TEST_IMAGE_DATA_H_
 #define PPAPI_TESTS_TEST_IMAGE_DATA_H_
 
 #include "ppapi/tests/test_case.h"
 
 struct PPB_ImageData;
 
 class TestImageData : public TestCase {
  public:
   TestImageData(TestingInstance* instance) : TestCase(instance) {}
 
   // TestCase implementation.
   virtual bool Init();
-  virtual void RunTest();
+  virtual void RunTests(const std::string& filter);
 
  private:
   std::string TestInvalidFormat();
   std::string TestInvalidSize();
   std::string TestHugeSize();
   std::string TestInitToZero();
   std::string TestIsImageData();
 
   // Used by the tests that access the C API directly.
   const PPB_ImageData* image_data_interface_;
 };
 
 #endif  // PPAPI_TESTS_TEST_IMAGE_DATA_H_