Blacklist partial swaps on linux

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index d6f9fc89a47a18c7c4da25353db9f757a122e3c8..736854e2f6e2069968a7b40382f67a2952fcac0f 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -1702,6 +1702,7 @@ class GLES2DecoderImpl : public GLES2Decoder,
   bool has_robustness_extension_;
   GLenum reset_status_;
   bool reset_by_robustness_extension_;
+  bool supports_post_sub_buffer_;
 
   // These flags are used to override the state of the shared feature_info_
   // member.  Because the same FeatureInfo instance may be shared among many
@@ -2207,6 +2208,7 @@ GLES2DecoderImpl::GLES2DecoderImpl(ContextGroup* group)
       has_robustness_extension_(false),
       reset_status_(GL_NO_ERROR),
       reset_by_robustness_extension_(false),
+      supports_post_sub_buffer_(false),
       force_webgl_glsl_validation_(false),
       derivatives_explicitly_enabled_(false),
       frag_depth_explicitly_enabled_(false),
@@ -2567,6 +2569,12 @@ bool GLES2DecoderImpl::Initialize(
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
   }
 
+  supports_post_sub_buffer_ = surface->SupportsPostSubBuffer();
+  if (feature_info_->workarounds()
+          .disable_post_sub_buffers_for_onscreen_surfaces &&
+      !surface->IsOffscreen())
+    supports_post_sub_buffer_ = false;
+
   if (feature_info_->workarounds().reverse_point_sprite_coord_origin) {
     glPointParameteri(GL_POINT_SPRITE_COORD_ORIGIN, GL_LOWER_LEFT);
   }
@@ -2619,7 +2627,7 @@ Capabilities GLES2DecoderImpl::GetCapabilities() {
   caps.iosurface = true;
 #endif
 
-  caps.post_sub_buffer = surface_->HasExtension("GL_CHROMIUM_post_sub_buffer");
+  caps.post_sub_buffer = supports_post_sub_buffer_;
 
   return caps;
 }
@@ -7433,7 +7441,7 @@ error::Error GLES2DecoderImpl::HandlePixelStorei(
 error::Error GLES2DecoderImpl::HandlePostSubBufferCHROMIUM(
     uint32 immediate_data_size, const cmds::PostSubBufferCHROMIUM& c) {
   TRACE_EVENT0("gpu", "GLES2DecoderImpl::HandlePostSubBufferCHROMIUM");
-  if (!surface_->HasExtension("GL_CHROMIUM_post_sub_buffer")) {
+  if (!supports_post_sub_buffer_) {
     LOCAL_SET_GL_ERROR(
         GL_INVALID_OPERATION,
         "glPostSubBufferCHROMIUM", "command not supported by surface");
@@ -7627,9 +7635,8 @@ error::Error GLES2DecoderImpl::HandleGetString(
         } else {
           extensions = feature_info_->extensions().c_str();
         }
-        std::string surface_extensions = surface_->GetExtensions();
-        if (!surface_extensions.empty())
-          extensions += " " + surface_extensions;
+        if (supports_post_sub_buffer_)
+          extensions += " GL_CHROMIUM_post_sub_buffer";
         str = extensions.c_str();
       }
       break;