Report lost context from GLES2Implementation based on share group state.

gpu/command_buffer/tests/gl_manager.cc

Index: gpu/command_buffer/tests/gl_manager.cc
diff --git a/gpu/command_buffer/tests/gl_manager.cc b/gpu/command_buffer/tests/gl_manager.cc
index 182e58dd085360421db980b2db3819a32a94dcf4..f11ea71fe04f03dbfe67682b0f241c9255a7aa57 100644
--- a/gpu/command_buffer/tests/gl_manager.cc
+++ b/gpu/command_buffer/tests/gl_manager.cc
@@ -584,11 +584,6 @@ void GLManager::SetLock(base::Lock*) {
   NOTIMPLEMENTED();
 }
 
-bool GLManager::IsGpuChannelLost() {
-  NOTIMPLEMENTED();
-  return false;
-}
-
 void GLManager::EnsureWorkVisible() {
   // This is only relevant for out-of-process command buffers.
 }