ui/compositor: Provide its own 'in process' ContextProvider.

ui/compositor/test/in_process_context_factory.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 "ui/compositor/test/in_process_context_factory.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/threading/thread.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/context_provider.h"
 #include "cc/output/output_surface_client.h"
 #include "cc/surfaces/surface_id_allocator.h"
 #include "cc/test/pixel_test_output_surface.h"
 #include "cc/test/test_shared_bitmap_manager.h"
 #include "gpu/blink/webgraphicscontext3d_in_process_command_buffer_impl.h"
 #include "gpu/command_buffer/client/context_support.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "ui/compositor/compositor_switches.h"
 #include "ui/compositor/reflector.h"
+#include "ui/compositor/test/in_process_context_provider.h"
 #include "ui/gl/gl_implementation.h"
 #include "ui/gl/gl_surface.h"
-#include "webkit/common/gpu/context_provider_in_process.h"
 
 namespace ui {
 namespace {
 
 // An OutputSurface implementation that directly draws and swaps to an actual
 // GL surface.
 class DirectOutputSurface : public cc::OutputSurface {
  public:
   explicit DirectOutputSurface(
       const scoped_refptr<cc::ContextProvider>& context_provider)
@@ skipping 53 matching lines @@
     bool software_fallback) {
   DCHECK(!software_fallback);
   blink::WebGraphicsContext3D::Attributes attrs;
   attrs.depth = false;
   attrs.stencil = false;
   attrs.antialias = false;
   attrs.shareResources = true;
   bool lose_context_when_out_of_memory = true;
 
   using gpu_blink::WebGraphicsContext3DInProcessCommandBufferImpl;
   scoped_ptr<WebGraphicsContext3DInProcessCommandBufferImpl> context3d(

[tfarina, 2015/01/20 23:23:52]

Is about this that are talking about or is it something else? Sorry, I'm not
terrible familiar with these classes.

[piman, 2015/01/21 00:10:23]

Right, the current code creates a
WebGraphicsContext3DInProcessCommandBufferImpl, that gets wrapped into a
InProcessContextProvider, that uses its GLES2Implementation.

WebGraphicsContext3D*Impl is a wrapper around the GLES2Implementation, that can
be passed to blink (e.g. for WebGL).

But for the UI, we never pass it to blink, and the
WebGraphicsContext3DInProcessCommandBufferImpl is just a container for the
GLInProcessContext and the GLES2Implementation.

So instead, we could have the InProcessContextProvider own the
GLInProcessContext and GLES2Implementation directly.

This code would change, instead of creating a
WebGraphicsContext3DInProcessCommandBufferImpl from the compositor->widget(), it
would create a InProcessContextProvider, passing it the compositor->widget, and
it would directly create the GLInProcessContext and GLES2Implementation (the
same way WebGraphicsContext3DInProcessCommandBufferImpl::CreateViewContext does
today).

That way, we could completely remove the gpu/blink dependency from
ui/compositor. It would also reduce the duplication.

       WebGraphicsContext3DInProcessCommandBufferImpl::CreateViewContext(
           attrs, lose_context_when_out_of_memory, compositor->widget()));
   CHECK(context3d);
 
-  using webkit::gpu::ContextProviderInProcess;
-  scoped_refptr<ContextProviderInProcess> context_provider =
-      ContextProviderInProcess::Create(context3d.Pass(), "UICompositor");
+  scoped_refptr<InProcessContextProvider> context_provider =
+      InProcessContextProvider::Create(context3d.Pass(), "UICompositor");
 
   if (use_test_surface_) {
     bool flipped_output_surface = false;
     compositor->SetOutputSurface(make_scoped_ptr(new cc::PixelTestOutputSurface(
         context_provider, flipped_output_surface)));
   } else {
     compositor->SetOutputSurface(
         make_scoped_ptr(new DirectOutputSurface(context_provider)));
   }
 }
 
 scoped_refptr<Reflector> InProcessContextFactory::CreateReflector(
     Compositor* mirroed_compositor,
     Layer* mirroring_layer) {
   return new Reflector();
 }
 
 void InProcessContextFactory::RemoveReflector(
     scoped_refptr<Reflector> reflector) {}
 
 scoped_refptr<cc::ContextProvider>
 InProcessContextFactory::SharedMainThreadContextProvider() {
   if (shared_main_thread_contexts_.get() &&
       !shared_main_thread_contexts_->DestroyedOnMainThread())
     return shared_main_thread_contexts_;
 
   bool lose_context_when_out_of_memory = false;
-  shared_main_thread_contexts_ =
-      webkit::gpu::ContextProviderInProcess::CreateOffscreen(
-          lose_context_when_out_of_memory);
+  shared_main_thread_contexts_ = InProcessContextProvider::CreateOffscreen(
+      lose_context_when_out_of_memory);
   if (shared_main_thread_contexts_.get() &&
       !shared_main_thread_contexts_->BindToCurrentThread())
     shared_main_thread_contexts_ = NULL;
 
   return shared_main_thread_contexts_;
 }
 
 void InProcessContextFactory::RemoveCompositor(Compositor* compositor) {}
 
 bool InProcessContextFactory::DoesCreateTestContexts() { return false; }
@@ skipping 17 matching lines @@
 InProcessContextFactory::CreateSurfaceIdAllocator() {
   return make_scoped_ptr(
       new cc::SurfaceIdAllocator(next_surface_id_namespace_++));
 }
 
 void InProcessContextFactory::ResizeDisplay(ui::Compositor* compositor,
                                             const gfx::Size& size) {
 }
 
 }  // namespace ui