command_buffer: Implement path rendering functions for CHROMIUM_path_rendering

gpu/command_buffer/service/feature_info.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 "gpu/command_buffer/service/feature_info.h"
 
 #include <set>
 
 #include "base/command_line.h"
 #include "base/macros.h"
@@ skipping 988 matching lines @@
 
       AddExtensionString("GL_KHR_blend_equation_advanced");
       feature_flags_.blend_equation_advanced = true;
       feature_flags_.blend_equation_advanced_coherent =
           blend_equation_advanced_coherent;
     }
   }
 
   if (extensions.Contains("GL_NV_path_rendering")) {
     if (extensions.Contains("GL_EXT_direct_state_access") ||
         gl_version_info_->is_es3) {

[piman, 2015/06/24 03:27:44]

Can we gate this behind a command-line flag? We're adding a significant security
surface with a complex extension, it's a good idea to be conservative here. Once
we prove the end-to-end benefits, we can turn on by default.

[Kimmo Kinnunen, 2015/06/24 12:49:01]

Done.

       AddExtensionString("GL_CHROMIUM_path_rendering");
       feature_flags_.chromium_path_rendering = true;
       validators_.g_l_state.AddValue(GL_PATH_MODELVIEW_MATRIX_CHROMIUM);
       validators_.g_l_state.AddValue(GL_PATH_PROJECTION_MATRIX_CHROMIUM);
+      validators_.g_l_state.AddValue(GL_PATH_STENCIL_FUNC_CHROMIUM);
+      validators_.g_l_state.AddValue(GL_PATH_STENCIL_REF_CHROMIUM);
+      validators_.g_l_state.AddValue(GL_PATH_STENCIL_VALUE_MASK_CHROMIUM);
     }
   }
 
   if ((gl_version_info_->is_es3 || gl_version_info_->is_desktop_core_profile ||
        extensions.Contains("GL_EXT_texture_rg") ||
        extensions.Contains("GL_ARB_texture_rg")) &&
       IsGL_REDSupportedOnFBOs()) {
     feature_flags_.ext_texture_rg = true;
     AddExtensionString("GL_EXT_texture_rg");
 
@@ skipping 109 matching lines @@
   if (pos == std::string::npos) {
     extensions_ += (extensions_.empty() ? "" : " ") + str;
   }
 }
 
 FeatureInfo::~FeatureInfo() {
 }
 
 }  // namespace gles2
 }  // namespace gpu