Re-land: cc: Implement shared worker contexts.

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 b90edd69a2f25dd9b17141dcebeb9b44df9be868..2f54b96f4f36c4fa7da16e0b6d9c1295bfae97df 100644
--- a/content/browser/android/in_process/synchronous_compositor_factory_impl.cc
+++ b/content/browser/android/in_process/synchronous_compositor_factory_impl.cc
@@ -24,6 +24,7 @@
 #include "content/renderer/render_thread_impl.h"
 #include "gpu/blink/webgraphicscontext3d_in_process_command_buffer_impl.h"
 #include "gpu/command_buffer/client/gl_in_process_context.h"
+#include "gpu/command_buffer/client/gles2_interface.h"
 #include "gpu/command_buffer/common/gles2_cmd_utils.h"
 #include "ui/gl/android/surface_texture.h"
 #include "ui/gl/gl_surface.h"
@@ -169,11 +170,39 @@ SynchronousCompositorFactoryImpl::CreateOutputSurface(
     scoped_refptr<content::FrameSwapMessageQueue> frame_swap_message_queue) {
   scoped_refptr<cc::ContextProvider> onscreen_context =
       CreateContextProviderForCompositor(surface_id, RENDER_COMPOSITOR_CONTEXT);
-  scoped_refptr<cc::ContextProvider> worker_context =
-      CreateContextProviderForCompositor(0, RENDER_WORKER_CONTEXT);
+
+  bool shared_worker_context_lost = false;
+  if (shared_worker_context_) {
+    base::AutoLock lock(*shared_worker_context_->GetLock());
+    if (shared_worker_context_->ContextGL()->GetGraphicsResetStatusKHR() !=
+        GL_NO_ERROR) {
+      shared_worker_context_lost = true;
+    }
+  }
+  // Note: shared worker context support requires |use_ipc_command_buffer_|.
+  if (use_ipc_command_buffer_ &&
+      (!shared_worker_context_ || shared_worker_context_lost)) {
+    // TODO(reveman): This limit is based on the usage required by async
+    // uploads. Determine what a good limit is now that async uploads are
+    // no longer used.
+    unsigned int mapped_memory_reclaim_limit =
+        (base::SysInfo::IsLowEndDevice() ? 2 : 6) * 1024 * 1024;
+    WebGraphicsContext3DCommandBufferImpl::SharedMemoryLimits mem_limits;
+    mem_limits.mapped_memory_reclaim_limit = mapped_memory_reclaim_limit;
+    scoped_ptr<WebGraphicsContext3DCommandBufferImpl> context =
+        CreateContext3D(0, GetDefaultAttribs(), mem_limits);
+    shared_worker_context_ =
+        make_scoped_refptr(new SynchronousCompositorContextProvider(
+            context.Pass(), RENDER_WORKER_CONTEXT));
+    if (!shared_worker_context_->BindToCurrentThread())
+      shared_worker_context_ = nullptr;
+    if (shared_worker_context_)
+      shared_worker_context_->SetupLock();
+  }
 
   return make_scoped_ptr(new SynchronousCompositorOutputSurface(
-      onscreen_context, worker_context, routing_id, frame_swap_message_queue));
+      onscreen_context, shared_worker_context_, routing_id,
+      frame_swap_message_queue));
 }
 
 InputHandlerManagerClient*
@@ -211,6 +240,9 @@ SynchronousCompositorFactoryImpl::CreateContextProviderForCompositor(
   // This is half of what RenderWidget uses because synchronous compositor
   // pipeline is only one frame deep. But twice of half for low end here
   // because 16bit texture is not supported.
+  // TODO(reveman): This limit is based on the usage required by async
+  // uploads. Determine what a good limit is now that async uploads are
+  // no longer used.
   unsigned int mapped_memory_reclaim_limit =
       (base::SysInfo::IsLowEndDevice() ? 2 : 6) * 1024 * 1024;
   blink::WebGraphicsContext3D::Attributes attributes = GetDefaultAttribs();