Revert of Remove DCHECK_IMPLIES/CHECK_IMPLIES.

ui/aura/window.cc

 // Copyright (c) 2012 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/aura/window.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 205 matching lines @@
 const WindowTreeHost* Window::GetHost() const {
   const Window* root_window = GetRootWindow();
   return root_window ? root_window->host_ : NULL;
 }
 
 void Window::Show() {
   DCHECK_EQ(visible_, layer()->GetTargetVisibility());
   // It is not allowed that a window is visible but the layers alpha is fully
   // transparent since the window would still be considered to be active but
   // could not be seen.
-  DCHECK(!visible_ || layer()->GetTargetOpacity() > 0.0f);
+  DCHECK_IMPLIES(visible_, layer()->GetTargetOpacity() > 0.0f);
   SetVisible(true);
 }
 
 void Window::Hide() {
   // RootWindow::OnVisibilityChanged will call ReleaseCapture.
   SetVisible(false);
 }
 
 bool Window::IsVisible() const {
   // Layer visibility can be inconsistent with window visibility, for example
@@ skipping 871 matching lines @@
     layer_name = "Unnamed Window";
 
   if (id_ != -1)
     layer_name += " " + base::IntToString(id_);
 
   layer()->set_name(layer_name);
 #endif
 }
 
 }  // namespace aura