AW: dump commandline state to logs for debugging

Similar to http://crrev/c/1266611, this dumps WebView's CommandLine
state (including the "--enable-features" and "--disable-features"
switches) to the log when the "dummy app"
("org.chromium.webview_log_verbosifier") is present.

Notably, this will give us an idea of whether the NetworkService is
enabled or not (FieldTrialList + CommandLine state + knowledge of
whether it is enabled-or-disabled-by-default should be sufficient).

This also adds a usage guide for the webview verbosifier app, including
the new commandline stuff.

Skipping presubmit for LOG(INFO).

NOPRESUBMIT=true

Bug: 929886, 918221
Test: Manual (following the steps in the new docs)
Test: Upload to gerrit > open file > click "gitiles"
Change-Id: I4c698d661c340f760e2a90da20439b44a56ea38b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1573087
Commit-Queue: Nate Fischer <ntfschr@chromium.org>
Reviewed-by: Richard Coles <torne@chromium.org>
Reviewed-by: Paul Miller <paulmiller@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#652642}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: a4ce9ccc717ef723fb4ce2fa7043612c126bebc5
1 file changed
tree: 29eeb5a78ea4ca55e177fd0359758942e95a0d96
  1. java/
  2. BUILD.gn
  3. generate_resource_rewriter.gni
  4. glue.gni