DevTools: only hide breakpoint editor on external blurs
DevTools: only hide breakpoint editor on external blurs

When opening the breakpoint editor and clicking on already-selected
text, focus can move from CodeMirror's scroller to its textarea.
This internal blur should not trigger a commit.

Screenshot: https://imgur.com/a/kzyWLYj

Bug: none
Change-Id: I096692aaf5fe38104e80c8628dee28d9ba21d2c5
Reviewed-on: https://chromium-review.googlesource.com/1181651
Reviewed-by: Dmitry Gozman <0ca14b32cbb359a30ac562af27dd84cc2813eacb@chromium.org>
Commit-Queue: Erik Luo <26192f5e05d23e5ee959014fb911d780e566545b@chromium.org>
Cr-Original-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#584663}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: f4a1ce740c2296ce905d4b006fe1d80c04abc2d7
dart-archive/devtools-frontend,dart-archive/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,dart-archive/devtools-frontend,ChromeDevTools/devtools-frontend,dart-archive/devtools-frontend,dart-archive/devtools-frontend,dart-archive/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend,ChromeDevTools/devtools-frontend