Web tests can be run with content_shell. To just dump the render tree, use the --run-web-tests flag:
out/Default/content_shell --run-web-tests foo.html
If you want to run web tests, build the target blink_tests; this includes all the other binaries required to run the tests.
You can run web tests using run_web_tests.py (in src/third_party/blink/tools).
third_party/blink/tools/run_web_tests.py storage/indexeddb
or execute the shell directly:
out/Default/content_shell --remote-debugging-port=9222
This allows you see how your changes look in Chromium, and even connect with devtools (by going to http://127.0.0.1:9222 from another window) to inspect your freshly compiled Blink.
On the Mac, use Content Shell.app, not content_shell.
out/Default/Content\ Shell.app/Contents/MacOS/Content\ Shell --remote-debugging-port=9222
To debug a renderer crash, ask Content Shell to wait for you to attach a debugger once it spawns a renderer process by adding the --renderer-startup-dialog flag:
out/Default/content_shell --renderer-startup-dialog
Debugging workers and other subprocesses is simpler with --wait-for-debugger-children, which can have one of two values: plugin or renderer.
To avoid writing (and maintaining!) yet another test controller, it is desirable to reuse an existing test controller. A possible solution would be to change DRT‘s test controller to not depend on DRT’s implementation of the Blink objects, but rather on the Blink interfaces. In addition, we would need to extract an interface from the test shell object that can be implemented by content shell. This would allow for directly using DRT's test controller in content shell.