Revert 289224 "Update ui::CompositorObserver instrumentation"

trunk/src/ui/compositor/compositor_observer.cc

 // Copyright 2014 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 "ui/compositor/compositor_observer.h"
 
 #include "base/logging.h"
 
 namespace ui {
 
-#if DCHECK_IS_ON
+#if defined(OS_MACOSX)
+// Debugging instrumentation for crbug.com/401630.
+// TODO(ccameron): remove this.
 CompositorObserver::CompositorObserver() : observing_count_(0) {}
 #else
 CompositorObserver::CompositorObserver() {}
 #endif
 
 CompositorObserver::~CompositorObserver() {
-  // TODO(ccameron): Make this check not fire on non-Mac platforms.
-  // http://crbug.com/403011
 #if defined(OS_MACOSX)
-  DCHECK_EQ(observing_count_, 0);
+  // Debugging instrumentation for crbug.com/401630.
+  // TODO(ccameron): remove this.
+  CHECK_EQ(observing_count_, 0);
 #endif
 }
 
 }