Various extension-related cleanup and simplifications.

test/cctest/profiler-extension.h

Index: test/cctest/profiler-extension.h
diff --git a/test/cctest/profiler-extension.h b/test/cctest/profiler-extension.h
index 00960b9a97cf28d18b3ccc26077841b5be3a37a9..392a7efbc753907f105c039a8f4a7aa85fa2065b 100644
--- a/test/cctest/profiler-extension.h
+++ b/test/cctest/profiler-extension.h
@@ -27,8 +27,14 @@
 //
 // Tests of profiles generator and utilities.
 
+#ifndef V8_TEST_CCTEST_PROFILER_EXTENSION_H_
+#define V8_TEST_CCTEST_PROFILER_EXTENSION_H_
+
 #include "../include/v8-profiler.h"
 
+namespace v8 {
+namespace internal {
+
 class ProfilerExtension : public v8::Extension {
  public:
   ProfilerExtension() : v8::Extension("v8/profiler", kSource) { }
@@ -41,3 +47,8 @@ class ProfilerExtension : public v8::Extension {
  private:
   static const char* kSource;
 };
+
+
+} }  // namespace v8::internal
+
+#endif