Migrate WebGL contexts on backgrounded tabs to the integrated GPU.

gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc b/gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc
index 631d185285c772942494a4ae53a0f70a20077a48..cd95815446c1f12a8c6443b9e4064064584a87b4 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc
@@ -3322,5 +3322,11 @@ error::Error GLES2DecoderPassthroughImpl::DoOverlayPromotionHintCHROMIUM(
   return error::kNoError;
 }
 
+error::Error GLES2DecoderPassthroughImpl::DoPerformanceHintCHROMIUM(
+    GLenum mode) {
+  NOTIMPLEMENTED();
+  return error::kNoError;
+}
+
 }  // namespace gles2
 }  // namespace gpu