Marshall Greenblatt 1174994211 Add initial chrome runtime support (see issue #2969)
Running `cefsimple --enable-chrome-runtime` will create and run a
Chrome browser window using the CEF app methods, and call
CefApp::OnContextInitialized as expected. CEF task methods also
work as expected in the main process. No browser-related methods or
callbacks are currently supported for the Chrome window, and the
application will exit when the last Chrome window closes.

The Chrome runtime requires resources.pak, chrome_100_percent.pak
and chrome_200_percent.pak files which were not previously built
with CEF. It shares the existing locales pak files which have been
updated to include additional Chrome-specific strings.

On Linux, the Chrome runtime requires GTK so use_gtk=true must be
specified via GN_DEFINES when building.

This change also refactors the CEF runtime, which can be tested in
the various supported modes by running:
$ cefclient
$ cefclient --multi-threaded-message-loop
$ cefclient --external-message-pump
2020-06-29 16:17:23 -04:00
..

There may be instances where CEF requires changes to the source code for
Chromium, Blink or third-party projects that are either not desired by those
projects or that have not yet been merged into the source code versions of those
projects used by CEF. To address this situation the CEF project adds a patch
capability as part of cef_create_projects[.bat|sh] build step. This patch
capability works as follows:

1. The CEF developer creates one or more patch files containing all required
   code changes and places those patch files in the "patches" subdirectory.
2. The CEF developer adds an entry for each patch file in the "patch.cfg" file.
3. When building CEF from source code the patch files are applied by the
   patcher.py tool via the cef_create_projects[.bat|sh] build step
4. When updating Chromium the patch_updater.py tool is used to update all patch
   files. See https://bitbucket.org/chromiumembedded/cef/wiki/ChromiumUpdate.md
   for more information about the update process.