Can you be more specific about the issue? What did you mean by "client" in this context?

Ah, sorry. I meant the blimp client. We enable this mode in the content layer on the engine side using switches::kUseRemoteCompositing. With this mode when the renderer is started, the complete cc::LayerTreeHost state is serialized on the engine (service) side and and sent to an android client, where it is consumed by the compositor to produce the final output.

This means that impl thread input handling, or basically what is done here, https://cs.chromium.org/chromium/src/ui/events/blink/input_handler_proxy.h, is being done on a compositor running on android device.

Since the device scale factor used by the compositor is what it received from the engine in the serialized LayerTree state, it ends up being incorrect for fling and pinch-zoom gestures handled on the compositor on the android client.

As we discussed offline, if you mixed android client & linux renderer without proper plumbing/settings, it won't work.

On the platform that is properly handled, these things should work. (for ex, 
pinch-to-zoom/gestures stuff are working on ChromeOS)

Sure, that makes sense. I just wanted to document that before this setting is enabled by default for all platforms, we have to make sure that it works for blimp as well.

Is there a meta-bug tracking the use-browser-zoom-for-dsf work? Perhaps I can mark this as blocking that bug so it doesn't slip by.

Khushal, can you adjust priority and add milestone if necessary?

The original bug isn't there anymore, and this isn't really required for blimp. The bug was just meant to be added to ensure that the UseZoomForDSF work doesn't end up forgetting about blimp.

oshima@, Could you point me to a bug for what I mentioned in #5, so I can make sure this one gets tracked there too?

Obsolete, WontFix.