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

ppapi/tests/test_instance_deprecated.cc

Index: ppapi/tests/test_instance_deprecated.cc
diff --git a/ppapi/tests/test_instance_deprecated.cc b/ppapi/tests/test_instance_deprecated.cc
index 9ff1e7e7e58eb9f5604750b7e61050056f963a88..1b558765a2f89cde077d6d8320d3086a6c9b1fee 100644
--- a/ppapi/tests/test_instance_deprecated.cc
+++ b/ppapi/tests/test_instance_deprecated.cc
@@ -77,8 +77,8 @@ bool TestInstance::Init() {
   return true;
 }
 
-void TestInstance::RunTest() {
-  RUN_TEST(ExecuteScript);
+void TestInstance::RunTests(const std::string& filter) {
+  RUN_TEST(ExecuteScript, filter);
 }
 
 pp::deprecated::ScriptableObject* TestInstance::CreateTestObject() {