Report lost context from GLES2Implementation based on share group state.

gpu/gles2_conform_support/egl/display.cc

Index: gpu/gles2_conform_support/egl/display.cc
diff --git a/gpu/gles2_conform_support/egl/display.cc b/gpu/gles2_conform_support/egl/display.cc
index db8a237d0434c6a0c3b842eb2e7f260dce535993..83a8a87b61f9c69f28fe2d94ad8db1c55fccfde9 100644
--- a/gpu/gles2_conform_support/egl/display.cc
+++ b/gpu/gles2_conform_support/egl/display.cc
@@ -359,11 +359,6 @@ void Display::SetLock(base::Lock*) {
   NOTIMPLEMENTED();
 }
 
-bool Display::IsGpuChannelLost() {
-  NOTIMPLEMENTED();
-  return false;
-}
-
 void Display::EnsureWorkVisible() {
   // This is only relevant for out-of-process command buffers.
 }