Disable window occlusion APIs when running browser tests

content/public/test/browser_test_base.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 "content/public/test/browser_test_base.h"
 
 #include <stddef.h>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 182 matching lines @@
 
   command_line->AppendSwitch(switches::kDomAutomationController);
 
   // It is sometimes useful when looking at browser test failures to know which
   // GPU blacklisting decisions were made.
   command_line->AppendSwitch(switches::kLogGpuControlListDecisions);
 
   if (use_software_compositing_)
     command_line->AppendSwitch(switches::kDisableGpu);
 
+  // The layout of windows on screen is unpredictable during, so disable

[Noel Gordon, 2016/03/04 01:57:32]

"during" -> "during tests" ?

[ccameron, 2016/03/06 23:09:08]

Thanks -- fixed.

+  // occlusion when running browser tests.
+  base::CommandLine::ForCurrentProcess()->AppendSwitch(
+      switches::kDisableBackgroundingOccludedWindows);
+
 #if defined(USE_AURA)
   // Most tests do not need pixel output, so we don't produce any. The command
   // line can override this behaviour to allow for visual debugging.
   if (command_line->HasSwitch(switches::kEnablePixelOutputInTests))
     enable_pixel_output_ = true;
 
   if (command_line->HasSwitch(switches::kDisableGLDrawingForTests)) {
     NOTREACHED() << "kDisableGLDrawingForTests should not be used as it"
                     "is chosen by tests. Use kEnablePixelOutputInTests "
                     "to enable pixel output.";
@@ skipping 143 matching lines @@
   use_software_compositing_ = true;
 }
 
 bool BrowserTestBase::UsingOSMesa() const {
   base::CommandLine* cmd = base::CommandLine::ForCurrentProcess();
   return cmd->GetSwitchValueASCII(switches::kUseGL) ==
          gfx::kGLImplementationOSMesaName;
 }
 
 }  // namespace content