Document more topics about running/debugging Content Shell

- The protocol mode
- Running HTTP web tests in Content Shell
- Running WPT tests in Content Shell
- Debugging with --single-process
- Debugging web tests
- Some corrections

Change-Id: I1d23d0f8a75b9d597edab153e4ec0ea9cdb7cb67
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1541863
Commit-Queue: Xianzhu Wang <[email protected]>
Reviewed-by: Robert Ma <[email protected]>
Cr-Commit-Position: refs/heads/master@{#645002}
diff --git a/docs/testing/web_tests.md b/docs/testing/web_tests.md
index e09fdd2..850a26c2 100644
--- a/docs/testing/web_tests.md
+++ b/docs/testing/web_tests.md
@@ -104,31 +104,39 @@
 test the SVG tests and run pixel tests, you would run:
 
 ```bash
-python third_party/blink/tools/run_web_tests.py -t Default svg
+[python] third_party/blink/tools/run_web_tests.py -t Default svg
 ```
 ***
 
 As a final quick-but-less-robust alternative, you can also just use the
-content_shell executable to run specific tests by using (for Windows):
+content_shell executable to run specific tests by using (example on Windows):
 
 ```bash
-out/Default/content_shell.exe --run-web-tests --no-sandbox full_test_source_path
+out/Default/content_shell.exe --run-web-tests <url>|<full_test_source_path>|<relative_test_path>
 ```
 
 as in:
 
 ```bash
-out/Default/content_shell.exe --run-web-tests --no-sandbox \
+out/Default/content_shell.exe --run-web-tests \
     c:/chrome/src/third_party/blink/web_tests/fast/forms/001.html
 ```
+or
+
+```bash
+out/Default/content_shell.exe --run-web-tests fast/forms/001.html
+```
 
 but this requires a manual diff against expected results, because the shell
-doesn't do it for you.
+doesn't do it for you. It also just dumps the text result only (as the dump of
+pixels and audio binary data is not human readable).
+See [Running Web Tests Using the Content Shell](web_tests_in_content_shell.md]
+for more details of running `content_shell`.
 
 To see a complete list of arguments supported, run:
 
 ```bash
-python run_web_tests.py --help
+python third_party/blink/tools/run_web_tests.py --help
 ```
 
 *** note