Move AW renderer compositor context to gpu thread

content/browser/android/in_process/synchronous_compositor_factory_impl.cc

Index: content/browser/android/in_process/synchronous_compositor_factory_impl.cc
diff --git a/content/browser/android/in_process/synchronous_compositor_factory_impl.cc b/content/browser/android/in_process/synchronous_compositor_factory_impl.cc
index 0fdf66ea9dfb8f0f849876ebc3f18eeb41b0dc5d..727125700b5f4e60ccf192e45cebedf902d20a61 100644
--- a/content/browser/android/in_process/synchronous_compositor_factory_impl.cc
+++ b/content/browser/android/in_process/synchronous_compositor_factory_impl.cc
@@ -4,6 +4,7 @@
 
 #include "content/browser/android/in_process/synchronous_compositor_factory_impl.h"
 
+#include "base/command_line.h"
 #include "base/observer_list.h"
 #include "content/browser/android/in_process/synchronous_compositor_external_begin_frame_source.h"
 #include "content/browser/android/in_process/synchronous_compositor_impl.h"
@@ -13,6 +14,7 @@
 #include "gpu/blink/webgraphicscontext3d_in_process_command_buffer_impl.h"
 #include "gpu/command_buffer/client/gl_in_process_context.h"
 #include "gpu/command_buffer/common/gles2_cmd_utils.h"
+#include "gpu/command_buffer/service/gpu_switches.h"
 #include "ui/gl/android/surface_texture.h"
 #include "ui/gl/gl_surface.h"
 #include "ui/gl/gl_surface_stub.h"
@@ -64,7 +66,8 @@ scoped_ptr<gpu::GLInProcessContext> CreateOffscreenContext(
 
 scoped_ptr<gpu::GLInProcessContext> CreateContext(
     scoped_refptr<gpu::InProcessCommandBuffer::Service> service,
-    const gpu::GLInProcessContextSharedMemoryLimits& mem_limits) {
+    const gpu::GLInProcessContextSharedMemoryLimits& mem_limits,
+    bool is_offscreen) {
   const gfx::GpuPreference gpu_preference = gfx::PreferDiscreteGpu;
   gpu::gles2::ContextCreationAttribHelper in_process_attribs;
   WebGraphicsContext3DImpl::ConvertAttributes(
@@ -74,7 +77,7 @@ scoped_ptr<gpu::GLInProcessContext> CreateContext(
   scoped_ptr<gpu::GLInProcessContext> context(gpu::GLInProcessContext::Create(
       service,
       NULL /* surface */,
-      false /* is_offscreen */,
+      is_offscreen,
       gfx::kNullAcceleratedWidget,
       gfx::Size(1, 1),
       NULL /* share_context */,
@@ -218,8 +221,16 @@ scoped_refptr<cc::ContextProvider> SynchronousCompositorFactoryImpl::
   // This is half of what RenderWidget uses because synchronous compositor
   // pipeline is only one frame deep.
   mem_limits.mapped_memory_reclaim_limit = 6 * 1024 * 1024;
+
+  scoped_refptr<gpu::InProcessCommandBuffer::Service> service;
+  bool is_offscreen = true;
+  if (!base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableAsyncPixelWithThreadedTextureMailboxes)) {
+    service = service_;
+    is_offscreen = false;
+  }
   return webkit::gpu::ContextProviderInProcess::Create(
-      WrapContext(CreateContext(service_, mem_limits)),
+      WrapContext(CreateContext(service, mem_limits, is_offscreen)),
       "Child-Compositor");
 }
 
@@ -288,9 +299,8 @@ SynchronousCompositorFactoryImpl::TryCreateStreamTextureFactory() {
   if (!video_context_provider_.get()) {
     DCHECK(service_.get());
 
-    video_context_provider_ = new VideoContextProvider(
-        CreateContext(service_,
-                      gpu::GLInProcessContextSharedMemoryLimits()));
+    video_context_provider_ = new VideoContextProvider(CreateContext(
+        service_, gpu::GLInProcessContextSharedMemoryLimits(), false));

[no sievers, 2015/01/15 20:26:05]

Can you put a comment that this needs to be treated as 'onscreen' because it
runs in the shared onscreen context (due to SurfaceTexture limitations when it
comes to share groups and such)?

[boliu, 2015/01/21 02:08:01]

I put something generic. Can you look again?

What is the share group limitation? I thought the issue is SurfaceTexture uses
eglImages underneath so can't be shared across threads with mailboxes.

[no sievers, 2015/01/23 21:48:35]

Yes you cannot create another texture from a SurfaceTexture. You can only have
one and the API is a bit weird. For example, you can detach/attach it to a
different context, but then it will delete your texture (although the caller
created it). Also, it doesn't know about GL share groups but does a pointer
comparison (!) in many APIs for the context it's used with.

   }
   return video_context_provider_;
 }