Add AwGLSurface and use it in WGC3D

Android can put the webview into an FBO, and compositor should draw into 
the FBO instead of directly on screen.  Use AwGLSurface and explicitly
set the FBO at the beginning of each hardware draw.

Add new APIs in GLInProcessContext and WGC3DIPCBI to allow the 
underlying GLSurface to be created separately.

BUG=251501

Review URL: https://chromiumcodereview.appspot.com/22277004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@216136 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 204 insertions, 78 deletions

diff --git a/gpu/command_buffer/client/gl_in_process_context.cc b/gpu/command_buffer/client/gl_in_process_context.cc
index 97f1715..cdbfc9f 100644
--- a/gpu/command_buffer/client/gl_in_process_context.cc
+++ b/gpu/command_buffer/client/gl_in_process_context.cc
@@ -53,16 +53,17 @@ class GLInProcessContextImpl
   explicit GLInProcessContextImpl();
   virtual ~GLInProcessContextImpl();
 
-  bool Initialize(bool is_offscreen,
+  bool Initialize(scoped_refptr<gfx::GLSurface> surface,
+                  bool is_offscreen,
                   bool share_resources,
                   gfx::AcceleratedWidget window,
                   const gfx::Size& size,
                   const char* allowed_extensions,
-                  const int32* attrib_list,
-                  gfx::GpuPreference gpu_preference,
-                  const base::Closure& context_lost_callback);
+                  const GLInProcessContextAttribs& attribs,
+                  gfx::GpuPreference gpu_preference);
 
   // GLInProcessContext implementation:
+  virtual void SetContextLostCallback(const base::Closure& callback) OVERRIDE;
   virtual void SignalSyncPoint(unsigned sync_point,
                                const base::Closure& callback) OVERRIDE;
   virtual void SignalQuery(unsigned query, const base::Closure& callback)
@@ -79,7 +80,7 @@ class GLInProcessContextImpl
   void Destroy();
   void PollQueryCallbacks();
   void CallQueryCallback(size_t index);
-  void OnContextLost(const base::Closure& callback);
+  void OnContextLost();
   void OnSignalSyncPoint(const base::Closure& callback);
 
   scoped_ptr<gles2::GLES2CmdHelper> gles2_helper_;
@@ -92,6 +93,7 @@ class GLInProcessContextImpl
 
   unsigned int share_group_id_;
   bool context_lost_;
+  base::Closure context_lost_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(GLInProcessContextImpl);
 };
@@ -147,9 +149,16 @@ gles2::GLES2Implementation* GLInProcessContextImpl::GetImplementation() {
   return gles2_implementation_.get();
 }
 
-void GLInProcessContextImpl::OnContextLost(const base::Closure& callback) {
+void GLInProcessContextImpl::SetContextLostCallback(
+    const base::Closure& callback) {
+  context_lost_callback_ = callback;
+}
+
+void GLInProcessContextImpl::OnContextLost() {
   context_lost_ = true;
-  callback.Run();
+  if (!context_lost_callback_.is_null()) {
+    context_lost_callback_.Run();
+  }
 }
 
 void GLInProcessContextImpl::OnSignalSyncPoint(const base::Closure& callback) {
@@ -159,47 +168,63 @@ void GLInProcessContextImpl::OnSignalSyncPoint(const base::Closure& callback) {
 }
 
 bool GLInProcessContextImpl::Initialize(
+    scoped_refptr<gfx::GLSurface> surface,
     bool is_offscreen,
     bool share_resources,
     gfx::AcceleratedWidget window,
     const gfx::Size& size,
     const char* allowed_extensions,
-    const int32* attrib_list,
-    gfx::GpuPreference gpu_preference,
-    const base::Closure& context_lost_callback) {
+    const GLInProcessContextAttribs& attribs,
+    gfx::GpuPreference gpu_preference) {
   DCHECK(size.width() >= 0 && size.height() >= 0);
 
-  std::vector<int32> attribs;
-  while (attrib_list) {
-    int32 attrib = *attrib_list++;
-    switch (attrib) {
-      // Known attributes
-      case ALPHA_SIZE:
-      case BLUE_SIZE:
-      case GREEN_SIZE:
-      case RED_SIZE:
-      case DEPTH_SIZE:
-      case STENCIL_SIZE:
-      case SAMPLES:
-      case SAMPLE_BUFFERS:
-        attribs.push_back(attrib);
-        attribs.push_back(*attrib_list++);
-        break;
-      case NONE:
-        attribs.push_back(attrib);
-        attrib_list = NULL;
-        break;
-      default:
-        attribs.push_back(NONE);
-        attrib_list = NULL;
-        break;
-    }
+  const int32 ALPHA_SIZE     = 0x3021;
+  const int32 BLUE_SIZE      = 0x3022;
+  const int32 GREEN_SIZE     = 0x3023;
+  const int32 RED_SIZE       = 0x3024;
+  const int32 DEPTH_SIZE     = 0x3025;
+  const int32 STENCIL_SIZE   = 0x3026;
+  const int32 SAMPLES        = 0x3031;
+  const int32 SAMPLE_BUFFERS = 0x3032;
+  const int32 NONE           = 0x3038;
+
+  std::vector<int32> attrib_vector;
+  if (attribs.alpha_size >= 0) {
+    attrib_vector.push_back(ALPHA_SIZE);
+    attrib_vector.push_back(attribs.alpha_size);
+  }
+  if (attribs.blue_size >= 0) {
+    attrib_vector.push_back(BLUE_SIZE);
+    attrib_vector.push_back(attribs.blue_size);
+  }
+  if (attribs.green_size >= 0) {
+    attrib_vector.push_back(GREEN_SIZE);
+    attrib_vector.push_back(attribs.green_size);
+  }
+  if (attribs.red_size >= 0) {
+    attrib_vector.push_back(RED_SIZE);
+    attrib_vector.push_back(attribs.red_size);
+  }
+  if (attribs.depth_size >= 0) {
+    attrib_vector.push_back(DEPTH_SIZE);
+    attrib_vector.push_back(attribs.depth_size);
+  }
+  if (attribs.stencil_size >= 0) {
+    attrib_vector.push_back(STENCIL_SIZE);
+    attrib_vector.push_back(attribs.stencil_size);
+  }
+  if (attribs.samples >= 0) {
+    attrib_vector.push_back(SAMPLES);
+    attrib_vector.push_back(attribs.samples);
+  }
+  if (attribs.sample_buffers >= 0) {
+    attrib_vector.push_back(SAMPLE_BUFFERS);
+    attrib_vector.push_back(attribs.sample_buffers);
   }
+  attrib_vector.push_back(NONE);
 
   base::Closure wrapped_callback =
-      base::Bind(&GLInProcessContextImpl::OnContextLost,
-                 AsWeakPtr(),
-                 context_lost_callback);
+      base::Bind(&GLInProcessContextImpl::OnContextLost, AsWeakPtr());
   command_buffer_.reset(new InProcessCommandBuffer());
 
   scoped_ptr<base::AutoLock> scoped_shared_context_lock;
@@ -223,15 +248,16 @@ bool GLInProcessContextImpl::Initialize(
     if (!share_group && !++share_group_id_)
         ++share_group_id_;
   }
-  if (!command_buffer_->Initialize(is_offscreen,
-                              share_resources,
-                              window,
-                              size,
-                              allowed_extensions,
-                              attribs,
-                              gpu_preference,
-                              wrapped_callback,
-                              share_group_id_)) {
+  if (!command_buffer_->Initialize(surface,
+                                   is_offscreen,
+                                   share_resources,
+                                   window,
+                                   size,
+                                   allowed_extensions,
+                                   attrib_vector,
+                                   gpu_preference,
+                                   wrapped_callback,
+                                   share_group_id_)) {
     LOG(INFO) << "Failed to initialize InProcessCommmandBuffer";
     return false;
   }
@@ -337,6 +363,16 @@ void GLInProcessContextImpl::SignalQuery(
 
 }  // anonymous namespace
 
+GLInProcessContextAttribs::GLInProcessContextAttribs()
+    : alpha_size(-1),
+      blue_size(-1),
+      green_size(-1),
+      red_size(-1),
+      depth_size(-1),
+      stencil_size(-1),
+      samples(-1),
+      sample_buffers(-1) {}
+
 // static
 GLInProcessContext* GLInProcessContext::CreateContext(
     bool is_offscreen,
@@ -344,20 +380,42 @@ GLInProcessContext* GLInProcessContext::CreateContext(
     const gfx::Size& size,
     bool share_resources,
     const char* allowed_extensions,
-    const int32* attrib_list,
-    gfx::GpuPreference gpu_preference,
-    const base::Closure& callback) {
+    const GLInProcessContextAttribs& attribs,
+    gfx::GpuPreference gpu_preference) {
   scoped_ptr<GLInProcessContextImpl> context(
       new GLInProcessContextImpl());
   if (!context->Initialize(
+      NULL /* surface */,
       is_offscreen,
       share_resources,
       window,
       size,
       allowed_extensions,
-      attrib_list,
-      gpu_preference,
-      callback))
+      attribs,
+      gpu_preference))
+    return NULL;
+
+  return context.release();
+}
+
+// static
+GLInProcessContext* GLInProcessContext::CreateWithSurface(
+    scoped_refptr<gfx::GLSurface> surface,
+    bool share_resources,
+    const char* allowed_extensions,
+    const GLInProcessContextAttribs& attribs,
+    gfx::GpuPreference gpu_preference) {
+  scoped_ptr<GLInProcessContextImpl> context(
+      new GLInProcessContextImpl());
+  if (!context->Initialize(
+      surface,
+      surface->IsOffscreen(),
+      share_resources,
+      gfx::kNullAcceleratedWidget,
+      surface->GetSize(),
+      allowed_extensions,
+      attribs,
+      gpu_preference))
     return NULL;
 
   return context.release();
diff --git a/gpu/command_buffer/client/gl_in_process_context.h b/gpu/command_buffer/client/gl_in_process_context.h
index 2d0754b..09f8140 100644
--- a/gpu/command_buffer/client/gl_in_process_context.h
+++ b/gpu/command_buffer/client/gl_in_process_context.h
@@ -9,6 +9,7 @@
 #include "base/compiler_specific.h"
 #include "gles2_impl_export.h"
 #include "ui/gfx/native_widget_types.h"
+#include "ui/gl/gl_surface.h"
 #include "ui/gl/gpu_preference.h"
 
 namespace gfx {
@@ -23,6 +24,20 @@ class GLES2Implementation;
 
 class GpuMemoryBufferFactory;
 
+// The default uninitialized value is -1.
+struct GLES2_IMPL_EXPORT GLInProcessContextAttribs {
+  GLInProcessContextAttribs();
+
+  int32 alpha_size;
+  int32 blue_size;
+  int32 green_size;
+  int32 red_size;
+  int32 depth_size;
+  int32 stencil_size;
+  int32 samples;
+  int32 sample_buffers;
+};
+
 class GLES2_IMPL_EXPORT GLInProcessContext {
  public:
   virtual ~GLInProcessContext() {}
@@ -30,20 +45,6 @@ class GLES2_IMPL_EXPORT GLInProcessContext {
   // Must be called before any GLInProcessContext instances are created.
   static void SetGpuMemoryBufferFactory(GpuMemoryBufferFactory* factory);
 
-  // GLInProcessContext configuration attributes. These are the same as used by
-  // EGL. Attributes are matched using a closest fit algorithm.
-  enum Attribute {
-    ALPHA_SIZE     = 0x3021,
-    BLUE_SIZE      = 0x3022,
-    GREEN_SIZE     = 0x3023,
-    RED_SIZE       = 0x3024,
-    DEPTH_SIZE     = 0x3025,
-    STENCIL_SIZE   = 0x3026,
-    SAMPLES        = 0x3031,
-    SAMPLE_BUFFERS = 0x3032,
-    NONE           = 0x3038  // Attrib list = terminator
-  };
-
   // Create a GLInProcessContext, if |is_offscreen| is true, renders to an
   // offscreen context. |attrib_list| must be NULL or a NONE-terminated list
   // of attribute/value pairs.
@@ -53,9 +54,21 @@ class GLES2_IMPL_EXPORT GLInProcessContext {
       const gfx::Size& size,
       bool share_resources,
       const char* allowed_extensions,
-      const int32* attrib_list,
-      gfx::GpuPreference gpu_preference,
-      const base::Closure& callback);
+      const GLInProcessContextAttribs& attribs,
+      gfx::GpuPreference gpu_preference);
+
+  // Create context with the provided GLSurface. All other arguments match
+  // CreateContext factory above. Can only be called if the command buffer
+  // service runs on the same thread as this client because GLSurface is not
+  // thread safe.
+  static GLInProcessContext* CreateWithSurface(
+      scoped_refptr<gfx::GLSurface> surface,
+      bool share_resources,
+      const char* allowed_extensions,
+      const GLInProcessContextAttribs& attribs,
+      gfx::GpuPreference gpu_preference);
+
+  virtual void SetContextLostCallback(const base::Closure& callback) = 0;
 
   virtual void SignalSyncPoint(unsigned sync_point,
                                const base::Closure& callback) = 0;
diff --git a/gpu/command_buffer/service/in_process_command_buffer.cc b/gpu/command_buffer/service/in_process_command_buffer.cc
index 766a7e0..ccbfb32 100644
--- a/gpu/command_buffer/service/in_process_command_buffer.cc
+++ b/gpu/command_buffer/service/in_process_command_buffer.cc
@@ -20,6 +20,7 @@
 #include "base/logging.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop_proxy.h"
+#include "base/sequence_checker.h"
 #include "base/threading/thread.h"
 #include "gpu/command_buffer/common/id_allocator.h"
 #include "gpu/command_buffer/service/command_buffer_service.h"
@@ -32,7 +33,6 @@
 #include "ui/gl/gl_context.h"
 #include "ui/gl/gl_image.h"
 #include "ui/gl/gl_share_group.h"
-#include "ui/gl/gl_surface.h"
 
 namespace gpu {
 
@@ -244,6 +244,7 @@ InProcessCommandBuffer::~InProcessCommandBuffer() {
 }
 
 bool InProcessCommandBuffer::IsContextLost() {
+  CheckSequencedThread();
   if (context_lost_ || !command_buffer_) {
     return true;
   }
@@ -252,11 +253,13 @@ bool InProcessCommandBuffer::IsContextLost() {
 }
 
 void InProcessCommandBuffer::OnResizeView(gfx::Size size, float scale_factor) {
+  CheckSequencedThread();
   DCHECK(!surface_->IsOffscreen());
   surface_->Resize(size);
 }
 
 bool InProcessCommandBuffer::MakeCurrent() {
+  CheckSequencedThread();
   command_buffer_lock_.AssertAcquired();
 
   if (!context_lost_ && decoder_->MakeCurrent())
@@ -268,6 +271,7 @@ bool InProcessCommandBuffer::MakeCurrent() {
 }
 
 void InProcessCommandBuffer::PumpCommands() {
+  CheckSequencedThread();
   command_buffer_lock_.AssertAcquired();
 
   if (!MakeCurrent())
@@ -277,12 +281,14 @@ void InProcessCommandBuffer::PumpCommands() {
 }
 
 bool InProcessCommandBuffer::GetBufferChanged(int32 transfer_buffer_id) {
+  CheckSequencedThread();
   command_buffer_lock_.AssertAcquired();
   command_buffer_->SetGetBuffer(transfer_buffer_id);
   return true;
 }
 
 bool InProcessCommandBuffer::Initialize(
+    scoped_refptr<gfx::GLSurface> surface,
     bool is_offscreen,
     bool share_resources,
     gfx::AcceleratedWidget window,
@@ -297,8 +303,13 @@ bool InProcessCommandBuffer::Initialize(
   context_lost_callback_ = WrapCallback(context_lost_callback);
   share_group_id_ = share_group_id;
 
-  base::WaitableEvent completion(true, false);
-  bool result = false;
+  if (surface) {
+    // GPU thread must be the same as client thread due to GLSurface not being
+    // thread safe.
+    sequence_checker_.reset(new base::SequenceChecker);
+    surface_ = surface;
+  }
+
   base::Callback<bool(void)> init_task =
       base::Bind(&InProcessCommandBuffer::InitializeOnGpuThread,
                  base::Unretained(this),
@@ -308,6 +319,9 @@ bool InProcessCommandBuffer::Initialize(
                  allowed_extensions,
                  attribs,
                  gpu_preference);
+
+  base::WaitableEvent completion(true, false);
+  bool result = false;
   QueueTask(
       base::Bind(&RunTaskWithResult<bool>, init_task, &result, &completion));
   completion.Wait();
@@ -321,6 +335,7 @@ bool InProcessCommandBuffer::InitializeOnGpuThread(
     const char* allowed_extensions,
     const std::vector<int32>& attribs,
     gfx::GpuPreference gpu_preference) {
+  CheckSequencedThread();
   // Use one share group for all contexts.
   CR_DEFINE_STATIC_LOCAL(scoped_refptr<gfx::GLShareGroup>, share_group,
                          (new gfx::GLShareGroup));
@@ -377,10 +392,12 @@ bool InProcessCommandBuffer::InitializeOnGpuThread(
 
   decoder_->set_engine(gpu_scheduler_.get());
 
-  if (is_offscreen)
-    surface_ = gfx::GLSurface::CreateOffscreenGLSurface(size);
-  else
-    surface_ = gfx::GLSurface::CreateViewGLSurface(window);
+  if (!surface_) {
+    if (is_offscreen)
+      surface_ = gfx::GLSurface::CreateOffscreenGLSurface(size);
+    else
+      surface_ = gfx::GLSurface::CreateViewGLSurface(window);
+  }
 
   if (!surface_.get()) {
     LOG(ERROR) << "Could not create GLSurface.";
@@ -448,6 +465,7 @@ bool InProcessCommandBuffer::InitializeOnGpuThread(
 }
 
 void InProcessCommandBuffer::Destroy() {
+  CheckSequencedThread();
   base::WaitableEvent completion(true, false);
   bool result = false;
   base::Callback<bool(void)> destroy_task = base::Bind(
@@ -458,6 +476,7 @@ void InProcessCommandBuffer::Destroy() {
 }
 
 bool InProcessCommandBuffer::DestroyOnGpuThread() {
+  CheckSequencedThread();
   command_buffer_.reset();
   // Clean up GL resources if possible.
   bool have_context = context_ && context_->MakeCurrent(surface_);
@@ -472,9 +491,15 @@ bool InProcessCommandBuffer::DestroyOnGpuThread() {
   return true;
 }
 
+void InProcessCommandBuffer::CheckSequencedThread() {
+  DCHECK(!sequence_checker_ ||
+         sequence_checker_->CalledOnValidSequencedThread());
+}
+
 unsigned int InProcessCommandBuffer::CreateImageForGpuMemoryBuffer(
     gfx::GpuMemoryBufferHandle buffer,
     gfx::Size size) {
+  CheckSequencedThread();
   unsigned int image_id;
   {
     // TODO: ID allocation should go through CommandBuffer
@@ -494,12 +519,14 @@ void InProcessCommandBuffer::CreateImageOnGpuThread(
     gfx::GpuMemoryBufferHandle buffer,
     gfx::Size size,
     unsigned int image_id) {
+  CheckSequencedThread();
   scoped_refptr<gfx::GLImage> gl_image =
       gfx::GLImage::CreateGLImageForGpuMemoryBuffer(buffer, size);
    decoder_->GetContextGroup()->image_manager()->AddImage(gl_image, image_id);
 }
 
 void InProcessCommandBuffer::RemoveImage(unsigned int image_id) {
+  CheckSequencedThread();
   {
     // TODO: ID allocation should go through CommandBuffer
     base::AutoLock lock(command_buffer_lock_);
@@ -514,10 +541,12 @@ void InProcessCommandBuffer::RemoveImage(unsigned int image_id) {
 }
 
 void InProcessCommandBuffer::RemoveImageOnGpuThread(unsigned int image_id) {
+  CheckSequencedThread();
   decoder_->GetContextGroup()->image_manager()->RemoveImage(image_id);
 }
 
 void InProcessCommandBuffer::OnContextLost() {
+  CheckSequencedThread();
   if (!context_lost_callback_.is_null()) {
     context_lost_callback_.Run();
     context_lost_callback_.Reset();
@@ -535,6 +564,7 @@ void InProcessCommandBuffer::OnContextLost() {
 }
 
 CommandBuffer::State InProcessCommandBuffer::GetStateFast() {
+  CheckSequencedThread();
   base::AutoLock lock(state_after_last_flush_lock_);
   if (state_after_last_flush_.generation - last_state_.generation < 0x80000000U)
     last_state_ = state_after_last_flush_;
@@ -542,19 +572,23 @@ CommandBuffer::State InProcessCommandBuffer::GetStateFast() {
 }
 
 CommandBuffer::State InProcessCommandBuffer::GetState() {
+  CheckSequencedThread();
   return GetStateFast();
 }
 
 CommandBuffer::State InProcessCommandBuffer::GetLastState() {
+  CheckSequencedThread();
   return last_state_;
 }
 
 int32 InProcessCommandBuffer::GetLastToken() {
+  CheckSequencedThread();
   GetStateFast();
   return last_state_.token;
 }
 
 void InProcessCommandBuffer::FlushOnGpuThread(int32 put_offset) {
+  CheckSequencedThread();
   ScopedEvent handle_flush(&flush_event_);
   base::AutoLock lock(command_buffer_lock_);
   command_buffer_->Flush(put_offset);
@@ -568,6 +602,7 @@ void InProcessCommandBuffer::FlushOnGpuThread(int32 put_offset) {
 }
 
 void InProcessCommandBuffer::Flush(int32 put_offset) {
+  CheckSequencedThread();
   if (last_state_.error != gpu::error::kNoError)
     return;
 
@@ -583,6 +618,7 @@ void InProcessCommandBuffer::Flush(int32 put_offset) {
 
 CommandBuffer::State InProcessCommandBuffer::FlushSync(int32 put_offset,
                                                        int32 last_known_get) {
+  CheckSequencedThread();
   if (put_offset == last_known_get || last_state_.error != gpu::error::kNoError)
     return last_state_;
 
@@ -598,6 +634,7 @@ CommandBuffer::State InProcessCommandBuffer::FlushSync(int32 put_offset,
 }
 
 void InProcessCommandBuffer::SetGetBuffer(int32 shm_id) {
+  CheckSequencedThread();
   if (last_state_.error != gpu::error::kNoError)
     return;
 
@@ -614,11 +651,13 @@ void InProcessCommandBuffer::SetGetBuffer(int32 shm_id) {
 
 gpu::Buffer InProcessCommandBuffer::CreateTransferBuffer(size_t size,
                                                          int32* id) {
+  CheckSequencedThread();
   base::AutoLock lock(command_buffer_lock_);
   return command_buffer_->CreateTransferBuffer(size, id);
 }
 
 void InProcessCommandBuffer::DestroyTransferBuffer(int32 id) {
+  CheckSequencedThread();
   base::Closure task = base::Bind(&CommandBuffer::DestroyTransferBuffer,
                                   base::Unretained(command_buffer_.get()),
                                   id);
@@ -637,10 +676,12 @@ uint32 InProcessCommandBuffer::InsertSyncPoint() {
 }
 void InProcessCommandBuffer::SignalSyncPoint(unsigned sync_point,
                                              const base::Closure& callback) {
+  CheckSequencedThread();
   QueueTask(WrapCallback(callback));
 }
 
 gpu::error::Error InProcessCommandBuffer::GetLastError() {
+  CheckSequencedThread();
   return last_state_.error;
 }
 
diff --git a/gpu/command_buffer/service/in_process_command_buffer.h b/gpu/command_buffer/service/in_process_command_buffer.h
index d2e103a..9bdbd49 100644
--- a/gpu/command_buffer/service/in_process_command_buffer.h
+++ b/gpu/command_buffer/service/in_process_command_buffer.h
@@ -17,8 +17,13 @@
 #include "gpu/gpu_export.h"
 #include "ui/gfx/gpu_memory_buffer.h"
 #include "ui/gfx/native_widget_types.h"
+#include "ui/gl/gl_surface.h"
 #include "ui/gl/gpu_preference.h"
 
+namespace base {
+class SequenceChecker;
+}
+
 namespace gfx {
 class GLContext;
 class GLImage;
@@ -57,7 +62,11 @@ class GPU_EXPORT InProcessCommandBuffer : public CommandBuffer {
 
   static void EnableVirtualizedContext();
 
-  bool Initialize(bool is_offscreen,
+  // If |surface| is not NULL, use it directly; in this case, the command
+  // buffer gpu thread must be the same as the client thread. Otherwise create
+  // a new GLSurface.
+  bool Initialize(scoped_refptr<gfx::GLSurface> surface,
+                  bool is_offscreen,
                   bool share_resources,
                   gfx::AcceleratedWidget window,
                   const gfx::Size& size,
@@ -118,6 +127,7 @@ class GPU_EXPORT InProcessCommandBuffer : public CommandBuffer {
   base::Closure WrapCallback(const base::Closure& callback);
   State GetStateFast();
   void QueueTask(const base::Closure& task) { queue_->QueueTask(task); }
+  void CheckSequencedThread();
 
   // Callbacks:
   void OnContextLost();
@@ -149,6 +159,10 @@ class GPU_EXPORT InProcessCommandBuffer : public CommandBuffer {
   State state_after_last_flush_;
   base::Lock state_after_last_flush_lock_;
 
+  // Only used with explicit scheduling and the gpu thread is the same as
+  // the client thread.
+  scoped_ptr<base::SequenceChecker> sequence_checker_;
+
   DISALLOW_COPY_AND_ASSIGN(InProcessCommandBuffer);
 };