Remove mutex.h and its uses.

mutex.h is now available as a part of MinGW itself.

Test: Successful build
Change-Id: I036ee37600a39130d6fbf293398585cfc58209ca

base/include/android-base/mutex.h

@@ -1,49 +0,0 @@
-/*
- * Copyright (C) 2016 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#pragma once
-
-#include <mutex>
-
-#include "android-base/macros.h"
-
-#if defined(_WIN32)
-#include <windows.h>
-
-namespace std {
-class mutex {
- public:
-  mutex() {
-    InitializeCriticalSection(&critical_section_);
-  }
-  ~mutex() {
-    DeleteCriticalSection(&critical_section_);
-  }
-
-  void lock() {
-    EnterCriticalSection(&critical_section_);
-  }
-
-  void unlock() {
-    LeaveCriticalSection(&critical_section_);
-  }
-
- private:
-  CRITICAL_SECTION critical_section_;
-  DISALLOW_COPY_AND_ASSIGN(mutex);
-};
-} // namespace std
-#endif

base/logging.cpp

@@ -44,7 +44,6 @@
 #include <vector>
 
 #include "android-base/macros.h"
-#include "android-base/mutex.h"
 #include "android-base/strings.h"
 
 // Headers for LogMessage::LogLine.

base/quick_exit.cpp

@@ -21,8 +21,6 @@
 #include <mutex>
 #include <vector>
 
-#include "android-base/mutex.h"
-
 namespace android {
 namespace base {