Improve scroll performance on Windows 10 with high precision touchpads.

Chrome scrolling performance on Windows 10 with high precision touch pads, is very janky and jumpy.
Windows 10 introduces a new API called Direct Manipulation which allows consumers to support smooth
scrolling, panning etc. Mouse wheel messages are dispatched differently based on whether the window
is a Direct manipulation consumer. Microsoft recommends supporting Direct Manipulation on Windows 10
and above.

This is an intial patch to do the bare minimum to register Chrome as a Direct Manipulation consumer.
The associated functionality is provided by the newly added DirectManipulationHelper class which lives
as a member of the LegacyRenderWidgetHostHWND class which ensures that these changes are isolated cleanly.

This does smoothen scrolling on these devices. However there is still work to be done


Review URL:

Cr-Commit-Position: refs/heads/master@{#342962}
8 files changed