Add EXT_color_buffer_half_float extension support in GPU commandbuffer service.

gpu/command_buffer/service/feature_info.cc

Index: gpu/command_buffer/service/feature_info.cc
diff --git a/gpu/command_buffer/service/feature_info.cc b/gpu/command_buffer/service/feature_info.cc
index f759bef8c188a26f710077f4d3e6cf8efed380b4..bf88c03cfccfe60f83f29644485ea1ae33dda6f9 100644
--- a/gpu/command_buffer/service/feature_info.cc
+++ b/gpu/command_buffer/service/feature_info.cc
@@ -432,7 +432,6 @@ void FeatureInfo::AddFeatures(const CommandLine& command_line) {
     texture_format_validators_[GL_LUMINANCE].AddValue(GL_FLOAT);
     texture_format_validators_[GL_LUMINANCE_ALPHA].AddValue(GL_FLOAT);
     validators_.pixel_type.AddValue(GL_FLOAT);
-    validators_.read_pixel_type.AddValue(GL_FLOAT);
     AddExtensionString("GL_OES_texture_float");
     if (enable_texture_float_linear) {
       AddExtensionString("GL_OES_texture_float_linear");
@@ -446,13 +445,51 @@ void FeatureInfo::AddFeatures(const CommandLine& command_line) {
     texture_format_validators_[GL_LUMINANCE].AddValue(GL_HALF_FLOAT_OES);
     texture_format_validators_[GL_LUMINANCE_ALPHA].AddValue(GL_HALF_FLOAT_OES);
     validators_.pixel_type.AddValue(GL_HALF_FLOAT_OES);
-    validators_.read_pixel_type.AddValue(GL_HALF_FLOAT_OES);
     AddExtensionString("GL_OES_texture_half_float");
     if (enable_texture_half_float_linear) {
       AddExtensionString("GL_OES_texture_half_float_linear");
     }
   }
 
+  bool enable_color_buffer_float = false;
+  if (extensions.Contains("GL_ARB_color_buffer_float")
+    || extensions.Contains("GL_ANGLE_color_buffer_float")) {
+    if (enable_texture_float)
+      enable_color_buffer_float = true;
+  }
+  if (enable_color_buffer_float) {
+    validators_.render_buffer_format.AddValue(GL_RGBA32F_EXT);
+    validators_.render_buffer_format.AddValue(GL_RGB32F_EXT);
+    AddExtensionString("GL_ANGLE_color_buffer_float");
+  }
+
+  bool enable_color_buffer_half_float = false;
+  if (extensions.Contains("GL_ARB_color_buffer_float")
+    || extensions.Contains("GL_EXT_color_buffer_half_float")) {
+    if (enable_texture_half_float)
+      enable_color_buffer_half_float = true;
+  }
+  if (enable_color_buffer_half_float) {
+    validators_.render_buffer_format.AddValue(GL_RGBA16F_EXT);
+    validators_.render_buffer_format.AddValue(GL_RGB16F_EXT);
+    // FIXME: read_pixel_type check should be improved.
+    // Only two format/type combinations are supported, one is
+    // RGBA/UNSIGNED_BYTE or RGBA/FLOAT, another is implementation-chosen
+    // format and type that can be queried.
+    validators_.read_pixel_type.AddValue(GL_HALF_FLOAT_OES);
+    AddExtensionString("GL_EXT_color_buffer_half_float");
+  }
+
+  if (enable_color_buffer_float || enable_color_buffer_half_float) {
+    validators_.frame_buffer_parameter.AddValue(
+       GL_FRAMEBUFFER_ATTACHMENT_COMPONENT_TYPE_EXT);
+    // FIXME: read_pixel_type check should be improved.
+    // Only two format/type combinations are supported, one is
+    // RGBA/UNSIGNED_BYTE or RGBA/FLOAT, another is implementation-chosen
+    // format and type that can be queried.
+    validators_.read_pixel_type.AddValue(GL_FLOAT);
+  }
+
   // Check for multisample support
   if (!disallowed_features_.multisampling) {
     bool ext_has_multisample =