Surfaceless OutputSurface implementation.

content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.cc

+// Copyright 2014 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 "content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.h"
+
+#include "cc/output/compositor_frame.h"
+#include "content/browser/compositor/buffered_output_surface.h"
+#include "content/browser/compositor/reflector_impl.h"
+#include "content/browser/gpu/gpu_surface_tracker.h"
+#include "content/common/gpu/client/context_provider_command_buffer.h"
+#include "gpu/GLES2/gl2extchromium.h"
+#include "gpu/command_buffer/client/gles2_interface.h"
+
+namespace content {
+
+GpuSurfacelessBrowserCompositorOutputSurface::
+    GpuSurfacelessBrowserCompositorOutputSurface(
+        const scoped_refptr<ContextProviderCommandBuffer>& context,
+        int surface_id,
+        IDMap<BrowserCompositorOutputSurface>* output_surface_map,
+        const scoped_refptr<ui::CompositorVSyncManager>& vsync_manager,
+        scoped_ptr<cc::OverlayCandidateValidator> overlay_candidate_validator,
+        unsigned internalformat)
+    : GpuBrowserCompositorOutputSurface(context,
+                                        surface_id,
+                                        output_surface_map,
+                                        vsync_manager,
+                                        overlay_candidate_validator.Pass()),
+      internalformat_(internalformat) {
+}
+
+GpuSurfacelessBrowserCompositorOutputSurface::
+    ~GpuSurfacelessBrowserCompositorOutputSurface() {
+}
+
+void GpuSurfacelessBrowserCompositorOutputSurface::SwapBuffers(
+    cc::CompositorFrame* frame) {
+  DCHECK(output_surface_);
+
+  const gfx::Size& size = frame->gl_frame_data->size;
+  gpu::gles2::GLES2Interface* gl = context_provider_->ContextGL();
+  gl->Finish();  // This will eventually be replaced by sync fences.

[piman, 2014/09/11 20:25:29]

I don't think the client should do this. This implies both a GL-level glFinish
in the GPU process, as well as a command-buffer finish, which blocks the client
until all the GL commands have executed.

I think you added this as a workaround for some drivers that need GL-level
synchronization. But that should be handled in the GPU process, in
GLSurfaceOzoneSurfaceless::SwapBuffers (or the ozone bits below).

[piman, 2014/09/12 21:58:29]

ping?

[achaulk, 2014/09/15 16:31:42]

Done.

+  gl->ScheduleOverlayPlaneCHROMIUM(0,
+                                   GL_OVERLAY_TRANSFORM_NONE_CHROMIUM,
+                                   output_surface_->current_tex_id(),
+                                   0,
+                                   0,
+                                   size.width(),
+                                   size.height(),
+                                   0,
+                                   0,
+                                   1.0f,
+                                   1.0f);
+  output_surface_->SwapBuffers();
+  GpuBrowserCompositorOutputSurface::SwapBuffers(frame);
+}
+
+void GpuSurfacelessBrowserCompositorOutputSurface::OnSwapBuffersComplete() {
+  DCHECK(output_surface_);
+  output_surface_->PageFlipComplete();
+  GpuBrowserCompositorOutputSurface::OnSwapBuffersComplete();
+}
+
+void GpuSurfacelessBrowserCompositorOutputSurface::BindFramebuffer() {
+  DCHECK(output_surface_);
+  output_surface_->BindFramebuffer();
+}
+
+void GpuSurfacelessBrowserCompositorOutputSurface::Reshape(
+    const gfx::Size& size,
+    float scale_factor) {
+  GpuBrowserCompositorOutputSurface::Reshape(size, scale_factor);
+  DCHECK(output_surface_);
+  output_surface_->Reshape(SurfaceSize(), scale_factor);
+}
+
+bool GpuSurfacelessBrowserCompositorOutputSurface::BindToClient(
+    cc::OutputSurfaceClient* client) {
+  DCHECK(output_surface_);

[piman, 2014/09/11 20:25:29]

This DCHECK looks wrong. The only place you're assigning output_surface_ is this
method.

BindToClient should be called only once. So I think what you want is:
DCHECK(!output_surface_)

and below, remove the if (!output_surface_)

+  if (!GpuBrowserCompositorOutputSurface::BindToClient(client))
+    return false;
+  if (!output_surface_) {
+    output_surface_.reset(
+        new BufferedOutputSurface(context_provider_, internalformat_));
+  }
+  return true;
+}
+
+}  // namespace content