Remove mutable from rtc::CriticalSection members.

webrtc/base/thread_unittest.cc

 /*
  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 146 matching lines @@
     CritScope scoped_lock(&cs_);
     flag_ = value;
     return *this;
   }
   bool get() const {
     CritScope scoped_lock(&cs_);
     return flag_;
   }
 
  private:
-  mutable CriticalSection cs_;
+  CriticalSection cs_;
   bool flag_;
 };
 
 // Function objects to test Thread::Invoke.
 struct FunctorA {
   int operator()() { return 42; }
 };
 class FunctorB {
  public:
   explicit FunctorB(AtomicBool* flag) : flag_(flag) {}
@@ skipping 539 matching lines @@
 };
 
 TEST_F(ComThreadTest, ComInited) {
   Thread* thread = new ComThread();
   EXPECT_TRUE(thread->Start());
   thread->Post(this, 0);
   EXPECT_TRUE_WAIT(done_, 1000);
   delete thread;
 }
 #endif