Implicitly ensure backbuffer creation on draw

Instead of having a special IPC channel to ensure a backbuffer is allocated
for a given GL context, we can create it implicitly on the first draw attempt
into FBO 0. If this fails, the context is considered lost.

BUG=181120

Review URL: https://codereview.chromium.org/112303002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240797 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 0 insertions, 31 deletions

diff --git a/content/common/gpu/client/command_buffer_proxy_impl.cc b/content/common/gpu/client/command_buffer_proxy_impl.cc
index 3b299063..768b427 100644
--- a/content/common/gpu/client/command_buffer_proxy_impl.cc
+++ b/content/common/gpu/client/command_buffer_proxy_impl.cc
@@ -448,13 +448,6 @@ void CommandBufferProxyImpl::Echo(const base::Closure& callback) {
   echo_tasks_.push(callback);
 }
 
-bool CommandBufferProxyImpl::EnsureBackbuffer() {
-  if (last_state_.error != gpu::error::kNoError)
-    return false;
-
-  return Send(new GpuCommandBufferMsg_EnsureBackbuffer(route_id_));
-}
-
 uint32 CommandBufferProxyImpl::InsertSyncPoint() {
   if (last_state_.error != gpu::error::kNoError)
     return 0;
diff --git a/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc b/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
index 8fea7d5..90cb9b9 100644
--- a/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
+++ b/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.cc
@@ -537,11 +537,6 @@ void WebGraphicsContext3DCommandBufferImpl::setVisibilityCHROMIUM(
 DELEGATE_TO_GL_3(discardFramebufferEXT, DiscardFramebufferEXT, WGC3Denum,
                  WGC3Dsizei, const WGC3Denum*)
 
-void WebGraphicsContext3DCommandBufferImpl::ensureBackbufferCHROMIUM() {
-  gl_->Flush();
-  command_buffer_->EnsureBackbuffer();
-}
-
 void WebGraphicsContext3DCommandBufferImpl::copyTextureToParentTextureCHROMIUM(
     WebGLId texture, WebGLId parentTexture) {
   NOTIMPLEMENTED();
diff --git a/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.h b/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.h
index 0dd4c1d..b5331eb 100644
--- a/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.h
+++ b/content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.h
@@ -503,8 +503,6 @@ class WebGraphicsContext3DCommandBufferImpl
   virtual void discardFramebufferEXT(WGC3Denum target,
                                      WGC3Dsizei numAttachments,
                                      const WGC3Denum* attachments);
-  virtual void ensureBackbufferCHROMIUM();
-
   virtual void copyTextureToParentTextureCHROMIUM(
       WebGLId texture, WebGLId parentTexture);
 
diff --git a/content/common/gpu/gpu_command_buffer_stub.cc b/content/common/gpu/gpu_command_buffer_stub.cc
index 4a1cbfd..44eaf90 100644
--- a/content/common/gpu/gpu_command_buffer_stub.cc
+++ b/content/common/gpu/gpu_command_buffer_stub.cc
@@ -213,8 +213,6 @@ bool GpuCommandBufferStub::OnMessageReceived(const IPC::Message& message) {
                                     OnCreateVideoDecoder)
     IPC_MESSAGE_HANDLER(GpuCommandBufferMsg_SetSurfaceVisible,
                         OnSetSurfaceVisible)
-    IPC_MESSAGE_HANDLER(GpuCommandBufferMsg_EnsureBackbuffer,
-                        OnEnsureBackbuffer)
     IPC_MESSAGE_HANDLER(GpuCommandBufferMsg_RetireSyncPoint,
                         OnRetireSyncPoint)
     IPC_MESSAGE_HANDLER(GpuCommandBufferMsg_SignalSyncPoint,
@@ -758,19 +756,6 @@ void GpuCommandBufferStub::OnSetSurfaceVisible(bool visible) {
     memory_manager_client_state_->SetVisible(visible);
 }
 
-void GpuCommandBufferStub::OnEnsureBackbuffer() {
-  TRACE_EVENT0("gpu", "GpuCommandBufferStub::OnEnsureBackbuffer");
-  if (!surface_.get())
-    return;
-  if (surface_->DeferDraws()) {
-    DCHECK(!IsScheduled());
-    channel_->RequeueMessage();
-  } else {
-    if (!surface_->SetBackbufferAllocation(true))
-      channel_->DestroySoon();
-  }
-}
-
 void GpuCommandBufferStub::AddSyncPoint(uint32 sync_point) {
   sync_points_.push_back(sync_point);
 }
diff --git a/content/common/gpu/gpu_messages.h b/content/common/gpu/gpu_messages.h
index 0ff3493..936a8a0 100644
--- a/content/common/gpu/gpu_messages.h
+++ b/content/common/gpu/gpu_messages.h
@@ -620,8 +620,6 @@ IPC_MESSAGE_ROUTED0(GpuCommandBufferMsg_EchoAck)
 // Send to stub on surface visibility change.
 IPC_MESSAGE_ROUTED1(GpuCommandBufferMsg_SetSurfaceVisible, bool /* visible */)
 
-IPC_MESSAGE_ROUTED0(GpuCommandBufferMsg_EnsureBackbuffer)
-
 // Sent to proxy when the gpu memory manager changes its memory allocation.
 IPC_MESSAGE_ROUTED1(GpuCommandBufferMsg_SetMemoryAllocation,
                     gpu::MemoryAllocation /* allocation */)