Automatically redraw the display on resume.

services/native_viewport/onscreen_context_provider.cc

Index: services/native_viewport/onscreen_context_provider.cc
diff --git a/services/native_viewport/onscreen_context_provider.cc b/services/native_viewport/onscreen_context_provider.cc
index c34ff865c36cc74aba74ba189973f1c2c3a8fc4c..a7ba14b3d9c8dcf78a1463901cef86f799485ad6 100644
--- a/services/native_viewport/onscreen_context_provider.cc
+++ b/services/native_viewport/onscreen_context_provider.cc
@@ -5,17 +5,21 @@
 #include "services/native_viewport/onscreen_context_provider.h"
 
 #include "services/gles2/command_buffer_driver.h"
-#include "services/gles2/command_buffer_impl.h"
 #include "services/gles2/gpu_state.h"
 
 namespace native_viewport {
 
 OnscreenContextProvider::OnscreenContextProvider(
     const scoped_refptr<gles2::GpuState>& state)
-    : state_(state), widget_(gfx::kNullAcceleratedWidget), binding_(this) {
+    : command_buffer_impl_(nullptr),
+      state_(state),
+      widget_(gfx::kNullAcceleratedWidget),
+      binding_(this) {
 }
 
 OnscreenContextProvider::~OnscreenContextProvider() {
+  if (command_buffer_impl_)
+    command_buffer_impl_->set_observer(nullptr);
 }
 
 void OnscreenContextProvider::Bind(
@@ -26,16 +30,26 @@ void OnscreenContextProvider::Bind(
 void OnscreenContextProvider::SetAcceleratedWidget(
     gfx::AcceleratedWidget widget) {
   widget_ = widget;
-  if (widget_ != gfx::kNullAcceleratedWidget &&
-      !pending_create_callback_.is_null())
-    CreateAndReturnCommandBuffer();
+
+  if (widget_ == gfx::kNullAcceleratedWidget) {
+    if (command_buffer_impl_)
+      command_buffer_impl_->DidLoseContext();
+    return;
+  }
+
+  if (pending_create_callback_.is_null())
+    return;
+
+  CreateAndReturnCommandBuffer();
 }
 
 void OnscreenContextProvider::Create(
     mojo::ViewportParameterListenerPtr viewport_parameter_listener,
     const CreateCallback& callback) {
-  if (!pending_create_callback_.is_null())
+  if (!pending_create_callback_.is_null()) {
+    DCHECK(!command_buffer_impl_);
     pending_create_callback_.Run(nullptr);
+  }
   pending_listener_ = viewport_parameter_listener.Pass();
   pending_create_callback_ = callback;
 
@@ -43,14 +57,20 @@ void OnscreenContextProvider::Create(
     CreateAndReturnCommandBuffer();
 }
 
+void OnscreenContextProvider::OnCommandBufferImplDestroyed() {
+  DCHECK(command_buffer_impl_);
+  command_buffer_impl_ = nullptr;
+}
+
 void OnscreenContextProvider::CreateAndReturnCommandBuffer() {
   mojo::CommandBufferPtr cb;
-  new gles2::CommandBufferImpl(
+  command_buffer_impl_ = new gles2::CommandBufferImpl(
       GetProxy(&cb), pending_listener_.Pass(), state_->control_task_runner(),
       state_->sync_point_manager(),
       make_scoped_ptr(new gles2::CommandBufferDriver(
           widget_, state_->share_group(), state_->mailbox_manager(),
           state_->sync_point_manager())));
+  command_buffer_impl_->set_observer(this);
   pending_create_callback_.Run(cb.Pass());
   pending_create_callback_.reset();
 }