Prepare for -Wall for third-party code, -Wextra for chromium_code

base/android/context_utils.cc

 // Copyright 2015 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.
 
 #include "base/android/context_utils.h"
 
 #include <jni.h>
 
 #include "base/android/scoped_java_ref.h"
 #include "base/lazy_instance.h"
@@ skipping 15 matching lines @@
   if (env->IsSameObject(g_application_context.Get().obj(), context.obj())) {
     // It's safe to set the context more than once if it's the same context.
     return;
   }
   DCHECK(g_application_context.Get().is_null());
   g_application_context.Get().Reset(context);
 }
 
 }  // namespace
 
-const jobject GetApplicationContext() {
+jobject GetApplicationContext() {
   DCHECK(!g_application_context.Get().is_null());
   return g_application_context.Get().obj();
 }
 
 void InitApplicationContext(JNIEnv* env, const JavaRef<jobject>& context) {
   SetNativeApplicationContext(env, context);
   Java_ContextUtils_initJavaSideApplicationContext(env, context.obj());
 }
 
 static void InitNativeSideApplicationContext(
     JNIEnv* env,
     const JavaParamRef<jclass>& clazz,
     const JavaParamRef<jobject>& context) {
   SetNativeApplicationContext(env, context);
 }
 
 bool RegisterContextUtils(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace android
 }  // namespace base