gpu: Implement GL_INTEL_framebuffer_CMAA via shaders in the GPU Service

ui/gl/gl_switches.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 "base/macros.h"
 #include "ui/gl/gl_switches.h"
 
 namespace gl {
 
 const char kGLImplementationDesktopName[]     = "desktop";
@@ skipping 75 matching lines @@
 // the GL output will not be correct but tests will run faster.
 const char kDisableGLDrawingForTests[] = "disable-gl-drawing-for-tests";
 
 // Forces the use of OSMesa instead of hardware gpu.
 const char kOverrideUseGLWithOSMesaForTests[] =
     "override-use-gl-with-osmesa-for-tests";
 
 // Disables specified comma separated GL Extensions if found.
 const char kDisableGLExtensions[] = "disable-gl-extensions";
 
+// Enables GL_INTEL_framebuffer_CMAA via shaders. Will be used if the platform
+// does not support GL_INTEL_framebuffer_CMAA and the context is at least
+// OpenGL ES 3.1 or OpenGL 3.0 with the required extensions.
+const char kEnableCMAAShaders[] = "enable-cmaa-shaders";
+
 // This is the list of switches passed from this file that are passed from the
 // GpuProcessHost to the GPU Process. Add your switch to this list if you need
 // to read it in the GPU process, else don't add it.
 const char* kGLSwitchesCopiedFromGpuProcessHost[] = {
     kDisableGpuVsync,
     kDisableD3D11,
     kEnableGPUServiceLogging,
     kEnableGPUServiceTracing,
     kEnableUnsafeES3APIs,
     kGpuNoContextLost,
     kDisableGLDrawingForTests,
     kOverrideUseGLWithOSMesaForTests,
     kUseANGLE,
     kDisableDirectComposition,
+    kEnableCMAAShaders,
 };
 const int kGLSwitchesCopiedFromGpuProcessHostNumSwitches =
     arraysize(kGLSwitchesCopiedFromGpuProcessHost);
 
 }  // namespace switches