Add a gyp flag to enable dcheck by default in release without

chrome/test/automation/automation_proxy_uitest.cc

 // Copyright (c) 2011 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 <string>
 
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
@@ skipping 79 matching lines @@
   AutomationProxyTest() {
     dom_automation_enabled_ = true;
     launch_arguments_.AppendSwitchASCII(switches::kLang, "en-US");
   }
 };
 
 TEST_F(AutomationProxyTest, GetBrowserWindowCount) {
   int window_count = 0;
   EXPECT_TRUE(automation()->GetBrowserWindowCount(&window_count));
   EXPECT_EQ(1, window_count);
-#ifdef NDEBUG
+#if defined(NDEBUG) && !defined(DCHECK_ALWAYS_ON)
   ASSERT_FALSE(automation()->GetBrowserWindowCount(NULL));
 #endif
 }
 
 TEST_F(AutomationProxyTest, GetBrowserWindow) {
   {
     scoped_refptr<BrowserProxy> window(automation()->GetBrowserWindow(0));
     ASSERT_TRUE(window.get());
   }
 
@@ skipping 1548 matching lines @@
   int diff_pixels_count = 0;
   for (int x = 0; x < img_size.width(); ++x) {
     for (int y = 0; y < img_size.height(); ++y) {
       if (*snapshot_bmp.getAddr32(x, y) != *reference_bmp.getAddr32(x, y)) {
         ++diff_pixels_count;
       }
     }
   }
   ASSERT_EQ(diff_pixels_count, 0);
 }