ImageCapture: move mojom from WebKit/public to media/

This CL moves image_capture.mojom from
{third_party/WebKit/public/platform/modules => media/mojo/interfaces}
so the generated data types (e.g. PhotoCapabilities{Ptr})
can be used from both Blink and media/capture locations.

Also capture.gypi is trivially relocated to capture/ folder.

Note that gyp files are -yay!- close to being finally
removed.

BUG=518807
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel,mac_blink_rel,win_blink_rel

Review-Url: https://codereview.chromium.org/2027023002
Cr-Commit-Position: refs/heads/master@{#397644}
19 files changed