Browser Plugin: PpapiCommandBufferProxy should see a lost context if the embedder has deleted the P…

ppapi/proxy/ppapi_command_buffer_proxy.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ppapi/proxy/ppapi_command_buffer_proxy.h"
 
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/proxy/proxy_channel.h"
 #include "ppapi/shared_impl/api_id.h"
 #include "ppapi/shared_impl/host_resource.h"
@@ skipping 81 matching lines @@
 
 bool PpapiCommandBufferProxy::Initialize() {
   return Send(new PpapiHostMsg_PPBGraphics3D_InitCommandBuffer(
       ppapi::API_ID_PPB_GRAPHICS_3D, resource_));
 }
 
 gpu::CommandBuffer::State PpapiCommandBufferProxy::GetState() {
   // Send will flag state with lost context if IPC fails.
   if (last_state_.error == gpu::error::kNoError) {
     gpu::CommandBuffer::State state;
+    bool success = false;
     if (Send(new PpapiHostMsg_PPBGraphics3D_GetState(
-             ppapi::API_ID_PPB_GRAPHICS_3D, resource_, &state))) {
-      UpdateState(state);
+             ppapi::API_ID_PPB_GRAPHICS_3D, resource_, &state, &success))) {
+      UpdateState(state, success);
     }
   }
 
   return last_state_;
 }
 
 gpu::CommandBuffer::State PpapiCommandBufferProxy::GetLastState() {
   return last_state_;
 }
 
@@ skipping 10 matching lines @@
   message->set_unblock(true);
   Send(message);
 }
 
 gpu::CommandBuffer::State PpapiCommandBufferProxy::FlushSync(int32 put_offset,
                                                    int32 last_known_get) {
   if (last_known_get == last_state_.get_offset) {
     // Send will flag state with lost context if IPC fails.
     if (last_state_.error == gpu::error::kNoError) {
       gpu::CommandBuffer::State state;
+      bool success = false;
       if (Send(new PpapiHostMsg_PPBGraphics3D_Flush(
                ppapi::API_ID_PPB_GRAPHICS_3D, resource_, put_offset,
-              last_known_get, &state))) {
-        UpdateState(state);
+              last_known_get, &state, &success))) {
+        UpdateState(state, success);
       }
     }
   } else {
     Flush(put_offset);
   }
   return last_state_;
 }
 
 void PpapiCommandBufferProxy::SetGetBuffer(int32 transfer_buffer_id) {
   if (last_state_.error == gpu::error::kNoError) {
@@ skipping 103 matching lines @@
   DCHECK(last_state_.error == gpu::error::kNoError);
 
   if (channel_->Send(msg))
     return true;
 
   last_state_.error = gpu::error::kLostContext;
   return false;
 }
 
 void PpapiCommandBufferProxy::UpdateState(
-    const gpu::CommandBuffer::State& state) {
+    const gpu::CommandBuffer::State& state,
+    bool success) {
   // Handle wraparound. It works as long as we don't have more than 2B state
   // updates in flight across which reordering occurs.
-  if (state.generation - last_state_.generation < 0x80000000U)
-    last_state_ = state;
+  if (success) {
+    if (state.generation - last_state_.generation < 0x80000000U) {
+      last_state_ = state;
+  } else
+    last_state_.error = gpu::error::kLostContext;
+    ++last_state_.generation;
+  }
 }
 
 }  // namespace proxy
 }  // namespace ppapi