commit fed56fa5117ab994d35372ec08622c02a9f1c579
author Tommy Nyquist <nyquist@google.com> Wed Jun 19 13:36:45 2019 -0700
committer Tommy Nyquist <nyquist@google.com> Wed Jun 19 13:36:45 2019 -0700
tree 15fecee9e1f15c97483ac7fa1987202e3728baa4
parent c63be46c502089deed3fc93217425e4b6ea2f517

Add support for opening traces from postMessage.

Up until now the only way for opening traces has been to either have
it available at a specific URL or as a local file.

However, going forward we also want to be able to push a trace to the
Perfetto UI from other domains, using postMessage().

This CL therefore adds a window messsage handler that is able to store
an incoming trace in the State's EngineConfig source property, which now
considers ArrayBuffer a valid type. When the trace has been received,
it is automatically opened.

Since the source origin will not be ui.perfetto.dev, the site that
triggers opening the window will not be able to listen to when the site
has fully loaded. We therefore add functionality to reply to any
message with the content 'PING' with a simple 'PONG', which tells
the source site that ui.perfetto.dev is ready to receive traces. The
next message is then typically the trace itself as an ArrayBuffer.

When the source is external, we do not want to keep the functionality
to share and download traces, so whenever an external trace is opened,
we set the UI in a localOnlyMode, which disables those functions in the
UI and adds decorations so this is intuitive to understand. This state
is reset when a trace of a different source type is opened.

Bug: 133367518
Change-Id: I738b7626669b27042f7c0edcf3beeb8176ed10b2