Hold the Pepper proxy lock for all Pepper GL calls.

BUG=418651

Committed: https://crrev.com/057f7a69dd40c93550b375b4287dba70d719316a
Cr-Commit-Position: refs/heads/master@{#302303}

Review URL: https://codereview.chromium.org/692683003

Cr-Commit-Position: refs/heads/master@{#303658}

ppapi/proxy/plugin_dispatcher.cc

@@ -211,6 +211,15 @@ bool PluginDispatcher::Send(IPC::Message* msg) {
   return SendMessage(msg);
 }
 
+bool PluginDispatcher::SendAndStayLocked(IPC::Message* msg) {
+  TRACE_EVENT2("ppapi proxy", "PluginDispatcher::SendAndStayLocked",
+               "Class", IPC_MESSAGE_ID_CLASS(msg->type()),
+               "Line", IPC_MESSAGE_ID_LINE(msg->type()));
+  if (!msg->is_reply())
+    msg->set_unblock(true);
+  return SendMessage(msg);
+}
+
 bool PluginDispatcher::OnMessageReceived(const IPC::Message& msg) {
   // We need to grab the proxy lock to ensure that we don't collide with the
   // plugin making pepper calls on a different thread.

ppapi/proxy/plugin_dispatcher.h

@@ -140,12 +140,15 @@ class PPAPI_PROXY_EXPORT PluginDispatcher
                              bool is_client);
 
   // Dispatcher overrides.
-  virtual bool IsPlugin() const;
-  virtual bool Send(IPC::Message* msg);
+  bool IsPlugin() const override;
+  bool Send(IPC::Message* msg) override;
+  // Unlike |Send()|, this function continues to hold the Pepper proxy lock
+  // unconditionally.
+  bool SendAndStayLocked(IPC::Message* msg) override;
 
   // IPC::Listener implementation.
-  virtual bool OnMessageReceived(const IPC::Message& msg);
-  virtual void OnChannelError();
+  bool OnMessageReceived(const IPC::Message& msg) override;
+  void OnChannelError() override;
 
   // Keeps track of which dispatcher to use for each instance, active instances
   // and tracks associated data like the current size.

ppapi/proxy/ppapi_command_buffer_proxy.cc

@@ -219,7 +219,10 @@ int32 PpapiCommandBufferProxy::CreateGpuMemoryBufferImage(
 bool PpapiCommandBufferProxy::Send(IPC::Message* msg) {
   DCHECK(last_state_.error == gpu::error::kNoError);
 
-  if (channel_->Send(msg))
+  // We need hold the Pepper proxy lock for sync IPC, because GPU command buffer
+  // may use a sync IPC with another lock held. It may cause deadlock.
+  // http://crbug.com/418651
+  if (channel_->SendAndStayLocked(msg))
     return true;
 
   last_state_.error = gpu::error::kLostContext;

ppapi/proxy/proxy_channel.cc

@@ -85,5 +85,9 @@ bool ProxyChannel::Send(IPC::Message* msg) {
   return false;
 }
 
+bool ProxyChannel::SendAndStayLocked(IPC::Message* msg) {
+  return Send(msg);
+}
+
 }  // namespace proxy
 }  // namespace ppapi

ppapi/proxy/proxy_channel.h

@@ -73,6 +73,8 @@ class PPAPI_PROXY_EXPORT ProxyChannel
   // IPC::Sender implementation.
   virtual bool Send(IPC::Message* msg) override;
 
+  virtual bool SendAndStayLocked(IPC::Message* msg);
+
   // IPC::Listener implementation.
   virtual void OnChannelError() override;