Revert of Mojo multiple command buffer support and sample

mojo/services/native_viewport/native_viewport_impl.cc

Index: mojo/services/native_viewport/native_viewport_impl.cc
diff --git a/mojo/services/native_viewport/native_viewport_impl.cc b/mojo/services/native_viewport/native_viewport_impl.cc
index e662a6d38a045d6c6b8adcccc1d79da60f26543c..8755dfd1c74b8f2dc5274e50698b51d89dfff11b 100644
--- a/mojo/services/native_viewport/native_viewport_impl.cc
+++ b/mojo/services/native_viewport/native_viewport_impl.cc
@@ -4,7 +4,6 @@
 
 #include "mojo/services/native_viewport/native_viewport_impl.h"
 
-#include "base/bind.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/time/time.h"
@@ -39,6 +38,7 @@
 void NativeViewportImpl::Create(RectPtr bounds) {
   platform_viewport_ = PlatformViewport::Create(this);
   platform_viewport_->Init(bounds.To<gfx::Rect>());
+  client()->OnCreated();
   OnBoundsChanged(bounds.To<gfx::Rect>());
 }
 
@@ -51,6 +51,7 @@
 }
 
 void NativeViewportImpl::Close() {
+  command_buffer_.reset();
   DCHECK(platform_viewport_);
   platform_viewport_->Close();
 }
@@ -59,14 +60,25 @@
   platform_viewport_->SetBounds(bounds.To<gfx::Rect>());
 }
 
+void NativeViewportImpl::CreateGLES2Context(
+    InterfaceRequest<CommandBuffer> command_buffer_request) {
+  if (command_buffer_ || command_buffer_request_.is_pending()) {
+    LOG(ERROR) << "Can't create multiple contexts on a NativeViewport";
+    return;
+  }
+  command_buffer_request_ = command_buffer_request.Pass();
+  CreateCommandBufferIfNeeded();
+}
+
 void NativeViewportImpl::OnBoundsChanged(const gfx::Rect& bounds) {
+  CreateCommandBufferIfNeeded();
   client()->OnBoundsChanged(Rect::From(bounds));
 }
 
 void NativeViewportImpl::OnAcceleratedWidgetAvailable(
     gfx::AcceleratedWidget widget) {
   widget_ = widget;
-  client()->OnCreated(reinterpret_cast<uint64_t>(widget));
+  CreateCommandBufferIfNeeded();
 }
 
 bool NativeViewportImpl::OnEvent(ui::Event* ui_event) {
@@ -96,12 +108,31 @@
 }
 
 void NativeViewportImpl::OnDestroyed() {
-  client()->OnDestroyed();
+  client()->OnDestroyed(base::Bind(&NativeViewportImpl::AckDestroyed,
+                                   base::Unretained(this)));
 }
 
 void NativeViewportImpl::AckEvent() {
   waiting_for_event_ack_ = false;
 }
 
+void NativeViewportImpl::CreateCommandBufferIfNeeded() {
+  if (!command_buffer_request_.is_pending())
+    return;
+  DCHECK(!command_buffer_.get());
+  if (widget_ == gfx::kNullAcceleratedWidget)
+    return;
+  gfx::Size size = platform_viewport_->GetSize();
+  if (size.IsEmpty())
+    return;
+  command_buffer_.reset(
+      new CommandBufferImpl(widget_, platform_viewport_->GetSize()));
+  WeakBindToRequest(command_buffer_.get(), &command_buffer_request_);
+}
+
+void NativeViewportImpl::AckDestroyed() {
+  command_buffer_.reset();
+}
+
 }  // namespace mojo