Remove ui_compositor_image_transport, it has no effect.

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index 46620828f85d7d7c261a207988eae4ecfe5f2ea0..19eaf29d6db9317861b4e8bafc4f5e0d28f96226 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -5140,11 +5140,6 @@ error::Error GLES2DecoderImpl::HandleResizeCHROMIUM(
   width = std::max(1U, width);
   height = std::max(1U, height);
 
-#if defined(OS_POSIX) && !defined(OS_MACOSX) && \
-    !defined(UI_COMPOSITOR_IMAGE_TRANSPORT)
-  // Make sure that we are done drawing to the back buffer before resizing.

[Nico, 2017/03/11 18:30:01]

I'm unsure about this bit; it might still be needed on Android? It looks like
this was added explicitly for linux here long ago:
https://codereview.chromium.org/5105006 So even though it might run on android
(not sure if we use glResizeCHROMIUM there), it's probably not intentional.

-  glFinish();
-#endif
   bool is_offscreen = !!offscreen_target_frame_buffer_.get();
   if (is_offscreen) {
     if (!ResizeOffscreenFramebuffer(gfx::Size(width, height))) {