quipper: PerfSerializer: Deserialize into events_; Use ParseRawEvents()

Deserialize into events_ instead of temporarily into parsed_events_, and
then moving the events into events_. The deserialization does not touch
the auxiliary information in ParsedEvent, so this convoluted path is not
necessary. Instead, reparse the events afterwards to fill in parsed_events_.
This means using the public ParseRawEvents() instead of the protected
ProcessEvents(), which can now become private.

TEST=unit tests
BUG=none

Change-Id: If2abdd4fa0ca419294cfab7863a11eb3711169e7
Reviewed-on: https://chromium-review.googlesource.com/262317
Reviewed-by: Simon Que <sque@chromium.org>
Commit-Queue: David Sharp <dhsharp@chromium.org>
Tested-by: David Sharp <dhsharp@chromium.org>
3 files changed