Update codesearch links

code.google.com redirects no longer work. This CL replaces links in /headless
to source.chromium.org equivalent.
This CL was uploaded by git cl split.

R=eseckler@chromium.org

Change-Id: I27b31f841ee3bd0b5b06f950a56707c92aca4414
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2392707
Auto-Submit: Josip Sokcevic <sokcevic@google.com>
Reviewed-by: Alexander Timin <altimin@chromium.org>
Commit-Queue: Alexander Timin <altimin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#805422}

headless/public/domains/README.md

 The client API domain classes are autogenerated. You can find them under the
 out-directory, e.g., out/Debug/gen/headless/public/devtools/domains, or in
-[Code Search](https://code.google.com/p/chromium/codesearch#search/&q=f%3Agen/headless/public/devtools/domains&sq=package:chromium&type=cs).
+[Code Search](https://source.chromium.org/chromium/chromium/src/+/HEAD:out/Debug/gen/headless/public/devtools/domains).