command_buffer: Implement CHROMIUM_framebuffer_mixed_samples extension

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 <vector>
 
 #include "base/command_line.h"
@@ skipping 150 matching lines @@
       ext_frag_depth(false),
       ext_shader_texture_lod(false),
       use_async_readpixels(false),
       map_buffer_range(false),
       ext_discard_framebuffer(false),
       angle_depth_texture(false),
       is_swiftshader(false),
       angle_texture_usage(false),
       ext_texture_storage(false),
       chromium_path_rendering(false),
+      chromium_framebuffer_mixed_samples(false),
       blend_equation_advanced(false),
       blend_equation_advanced_coherent(false),
       ext_texture_rg(false),
       chromium_image_ycbcr_420v(false),
       chromium_image_ycbcr_422(false),
       enable_subscribe_uniform(false),
       emulate_primitive_restart_fixed_index(false),
       ext_render_buffer_format_bgra8888(false),
       ext_multisample_compatibility(false),
       ext_blend_func_extended(false) {}
@@ skipping 980 matching lines @@
       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 (enable_gl_path_rendering_switch_ &&
+      !workarounds_.disable_gl_path_rendering &&
+      extensions.Contains("GL_NV_framebuffer_mixed_samples")) {
+    AddExtensionString("GL_CHROMIUM_framebuffer_mixed_samples");
+    feature_flags_.chromium_framebuffer_mixed_samples = true;
+    validators_.g_l_state.AddValue(GL_COVERAGE_MODULATION_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");
 
     validators_.texture_format.AddValue(GL_RED_EXT);
     validators_.texture_format.AddValue(GL_RG_EXT);
     validators_.texture_internal_format.AddValue(GL_RED_EXT);
@@ skipping 151 matching lines @@
   if (pos == std::string::npos) {
     extensions_ += (extensions_.empty() ? "" : " ") + str;
   }
 }
 
 FeatureInfo::~FeatureInfo() {
 }
 
 }  // namespace gles2
 }  // namespace gpu