PPAPI: Remove threading options; it's always on

ppapi/tests/test_case.h

Index: ppapi/tests/test_case.h
diff --git a/ppapi/tests/test_case.h b/ppapi/tests/test_case.h
index c2379d185618dff9cfc6841ce60e14baa5a4525f..9ffc8f6286e5c2aec6ad59e9c0f47e684c8a1fba 100644
--- a/ppapi/tests/test_case.h
+++ b/ppapi/tests/test_case.h
@@ -137,7 +137,6 @@ class TestCase {
   // Run the given test method on a background thread and return the result.
   template <class T>
   std::string RunOnThread(std::string(T::*test_to_run)()) {
-#ifdef ENABLE_PEPPER_THREADING
     if (!testing_interface_) {
       return "Testing blocking callbacks requires the testing interface. In "
              "Chrome, use the --enable-pepper-testing flag.";
@@ -152,10 +151,6 @@ class TestCase {
     RunOnThreadInternal(&ThreadedTestRunner<T>::ThreadFunction, &runner,
                         testing_interface_);
     return runner.result();
-#else
-    // If threading's not enabled, just treat it as success.
-    return std::string();
-#endif
   }
 
   // Pointer to the instance that owns us.