The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/281b1ee604a3095d93c5bed1eb05e84f57db6966

commit 281b1ee604a3095d93c5bed1eb05e84f57db6966
Author: sawtelle <sawtelle@google.com>
Date: Thu Jul 12 02:08:05 2018

[Picture in Picture] Create PictureInPictureControlEvent

This change creates a subclass of Event called
PictureInPictureControlEvent that can be called when
a custom control is clicked on the Picture in Picture Window
 - the reason for this event specifically is that it also
contains a String 'id', which is useful for a developer
to see which control was clicked.

Manual testing was done by initiating the call in
overlay_window_views.cc by calling controller_->ControlClick() and
confirming that the Event was triggered. An example can be seen at:
https://stevensawtelle.github.io/pictureinpicture
    /picture_in_picture_example.html

Note: There is still no built in way of assigning the string based on
the id of the control that was clicked - that will come in a future CL.
This CL is just to create the custom event.

Bug:  854271 
Change-Id: Idf8c290c7f7745af8f492d3b3169ba4cadb2386a
Reviewed-on: https://chromium-review.googlesource.com/1106615
Commit-Queue: Steven Sawtelle <sawtelle@google.com>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Reviewed-by: apacible <apacible@chromium.org>
Reviewed-by: François Beaufort <beaufort.francois@gmail.com>
Cr-Commit-Position: refs/heads/master@{#574462}
[modify] https://crrev.com/281b1ee604a3095d93c5bed1eb05e84f57db6966/third_party/WebKit/LayoutTests/webexposed/global-interface-listing-expected.txt
[modify] https://crrev.com/281b1ee604a3095d93c5bed1eb05e84f57db6966/third_party/blink/renderer/core/BUILD.gn
[modify] https://crrev.com/281b1ee604a3095d93c5bed1eb05e84f57db6966/third_party/blink/renderer/core/core_idl_files.gni
[modify] https://crrev.com/281b1ee604a3095d93c5bed1eb05e84f57db6966/third_party/blink/renderer/core/events/BUILD.gn
[add] https://crrev.com/281b1ee604a3095d93c5bed1eb05e84f57db6966/third_party/blink/renderer/core/events/picture_in_picture_control_event.cc
[add] https://crrev.com/281b1ee604a3095d93c5bed1eb05e84f57db6966/third_party/blink/renderer/core/events/picture_in_picture_control_event.h
[add] https://crrev.com/281b1ee604a3095d93c5bed1eb05e84f57db6966/third_party/blink/renderer/core/events/picture_in_picture_control_event.idl
[add] https://crrev.com/281b1ee604a3095d93c5bed1eb05e84f57db6966/third_party/blink/renderer/core/events/picture_in_picture_control_event_init.idl
[modify] https://crrev.com/281b1ee604a3095d93c5bed1eb05e84f57db6966/third_party/blink/renderer/modules/picture_in_picture/picture_in_picture_controller_impl.cc