[Element Capture #3] properly generate effect nodes

This Patch:
This patch contains a fix for element capture where
EffectPaintPropertyNode instances marked with an ID for element
capture do not get properly converted into EffectNodes. It also
includes a very minor cleanup to the element capture compositing
reasons, where CompositingReason::kElementCapture was ordered
incorrectly.

The Project:
Element level capture is a new mode of tab capture being implemented that allows developers to capture subsections of the DOM, meaning that occluding content is never captured (unless the currently existing region capture mode). For more information, Googlers may visit: go/element-capture

All developers are welcome to visit the W3 spec page at:
https://screen-share.github.io/element-capture/

Coming Up Next:
1. Adding a command line flag to enable a hack so that element
   capture can actually be enabled.
2. Modify the FrameSinkVideoCapturerImpl to enable element capture,
   fix issues with overlay calculation.
3. Working with eladlon@ to replace the hack with the proper
   restrictTo API.
4. Bug fixing and stabilizations.

Bug: 1418194
Change-Id: I39c2b48342f90c12125beec4bedcbf12e305e9b4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4779181


Reviewed-by: Philip Rogers <pdr@chromium.org>
Commit-Queue: Jordan Bayles <jophba@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1184824}