base: Fix/add header #ifndef guards.

base/android/jni_generator/sample_for_tests.h

 // Copyright (c) 2013 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 BASE_ANDROID_JNI_GENERATOR_SAMPLE_FOR_TESTS_H_
+#define BASE_ANDROID_JNI_GENERATOR_SAMPLE_FOR_TESTS_H_
+
 #include <jni.h>
 #include <map>
 #include <string>
 
 #include "base/android/jni_android.h"
 #include "base/basictypes.h"
 
 namespace base {
 namespace android {
 
@@ skipping 26 matching lines @@
       JNIEnv* env, jobject obj);
 
  private:
   std::map<long, std::string> map_;
 
   DISALLOW_COPY_AND_ASSIGN(CPPClass);
 };
 
 }  // namespace android
 }  // namespace base
+
+#endif  // BASE_ANDROID_JNI_GENERATOR_SAMPLE_FOR_TESTS_H_