Ignore custom offscreen surface unless explicitly opted in

gpu/ipc/service/gpu_command_buffer_stub.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/ipc/service/gpu_command_buffer_stub.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 637 matching lines @@
   sync_point_client_ = base::MakeUnique<SyncPointClient>(
       channel_->sync_point_manager(),
       channel_->GetSyncPointOrderData(stream_id_),
       CommandBufferNamespace::GPU_IO, command_buffer_id_);
 
   executor_->SetPreemptByFlag(channel_->preempted_flag());
 
   decoder_->set_engine(executor_.get());
 
   if (offscreen) {
-    if (init_params.attribs.depth_size > 0) {
-      surface_format.SetDepthBits(init_params.attribs.depth_size);
+    // Do we want to create an offscreen rendering context suitable
+    // for directly drawing to a separately supplied surface? In that
+    // case, we must ensure that the surface used for context creation
+    // is compatible with the requested attributes. This is explicitly
+    // opt-in since some context such as for NaCl request custom
+    // attributes but don't expect to get their own surface, and not
+    // all surface factories support custom formats.
+    if (init_params.attribs.own_offscreen_surface) {
+      if (init_params.attribs.depth_size > 0) {
+        surface_format.SetDepthBits(init_params.attribs.depth_size);
+      }
+      if (init_params.attribs.samples > 0) {
+        surface_format.SetSamples(init_params.attribs.samples);
+      }
+      if (init_params.attribs.stencil_size > 0) {
+        surface_format.SetStencilBits(init_params.attribs.stencil_size);
+      }
+      // Currently, we can't separately control alpha channel for surfaces,
+      // it's generally enabled by default except for RGB565 and (on desktop)
+      // smaller-than-32bit formats.
+      //
+      // TODO(klausw): use init_params.attribs.alpha_size here if possible.
     }
-    if (init_params.attribs.samples > 0) {
-      surface_format.SetSamples(init_params.attribs.samples);
-    }
-    if (init_params.attribs.stencil_size > 0) {
-      surface_format.SetStencilBits(init_params.attribs.stencil_size);
-    }
-    // Currently, we can't separately control alpha channel for surfaces,
-    // it's generally enabled by default except for RGB565 and (on desktop)
-    // smaller-than-32bit formats.
-    //
-    // TODO(klausw): use init_params.attribs.alpha_size here if possible.
     if (!surface_format.IsCompatible(default_surface->GetFormat())) {
       DVLOG(1) << __FUNCTION__ << ": Hit the OwnOffscreenSurface path";
       use_virtualized_gl_context_ = false;
       surface_ = gl::init::CreateOffscreenGLSurfaceWithFormat(gfx::Size(),
                                                               surface_format);
       if (!surface_) {
         DLOG(ERROR) << "Failed to create surface.";
         return false;
       }
     } else {
@@ skipping 546 matching lines @@
       command_buffer_->GetLastState().error == error::kLostContext)
     return;
 
   command_buffer_->SetContextLostReason(error::kUnknown);
   if (decoder_)
     decoder_->MarkContextLost(error::kUnknown);
   command_buffer_->SetParseError(error::kLostContext);
 }
 
 }  // namespace gpu