Report lost context from GLES2Implementation based on share group state.

mojo/gles2/command_buffer_client_impl.cc

Index: mojo/gles2/command_buffer_client_impl.cc
diff --git a/mojo/gles2/command_buffer_client_impl.cc b/mojo/gles2/command_buffer_client_impl.cc
index 1aa4d310c286906923b707b2a68ce1ead3bb5371..1d78f850f5f0c8d7139ddaee712f99dac4be037c 100644
--- a/mojo/gles2/command_buffer_client_impl.cc
+++ b/mojo/gles2/command_buffer_client_impl.cc
@@ -337,11 +337,6 @@ void CommandBufferClientImpl::MakeProgressAndUpdateState() {
 void CommandBufferClientImpl::SetLock(base::Lock* lock) {
 }
 
-bool CommandBufferClientImpl::IsGpuChannelLost() {
-  // This is only possible for out-of-process command buffers.
-  return false;
-}
-
 void CommandBufferClientImpl::EnsureWorkVisible() {
   // This is only relevant for out-of-process command buffers.
 }