New method added in Chrome 661 that works for a production build on unrooted devices.
Using
adb, write the flags to/data/local/tmp/chrome-command-line.For example:
~$ adb shell 'echo --unsafely-treat-insecure-origin-as-secure=http://a.test > /data/local/tmp/chrome-command-line'In
chrome://flags, turn onenable-command-line-on-non-rooted-devices.Force stop Chrome (the relaunch now button will not trigger the reading of the flags file, even though the danger snackbar will disagree).
Verify in chrome://version that this worked.
https://www.chromium.org/developers/how-tos/run-chromium-with-flags#TOC-Android
Answer from Josh Lee on Stack OverflowVideos
Do Chrome Flags work on all devices?
You can use Chrome Flags on both mobile and desktop browsers, but not all Chrome Flags are available on every device. Some are desktop or mobile-specific. However, Chrome will separate unavailable Flags and put them into the Unavailable tab.
Do Chrome Flags always become official features?
Chrome Flags are experimental features that the Google team is testing. The team will make these official Chrome features once they are in good working order, if they are deemed worthy. This isn’t always the case, though. Chrome Flags are often killed.
Is it safe to use Chrome Flags?
Using Chrome Flags is safe, but it can make your experience a bit buggy. The team also warns that you could lose data and compromise privacy. This is just Google being careful, though. The worst that can usually happen is that you’ll need to relaunch Chrome and turn off the Chrome Flags, if anything goes wrong.
New method added in Chrome 661 that works for a production build on unrooted devices.
Using
adb, write the flags to/data/local/tmp/chrome-command-line.For example:
~$ adb shell 'echo --unsafely-treat-insecure-origin-as-secure=http://a.test > /data/local/tmp/chrome-command-line'In
chrome://flags, turn onenable-command-line-on-non-rooted-devices.Force stop Chrome (the relaunch now button will not trigger the reading of the flags file, even though the danger snackbar will disagree).
Verify in chrome://version that this worked.
https://www.chromium.org/developers/how-tos/run-chromium-with-flags#TOC-Android
What you're doing is correct, but seems like you're writing the switches to the wrong file for Chrome (and note that the file that you write the switches to may vary based on the OS version [or maybe phone?] ).
I tried this on two different phones, and had to write to two different files! Hopefully one of them will work for you:
Phone 1: Nexus 6 with Android 6.0.1
Simply do the following in adb shell:
echo "chrome --sync-url" > /data/local/tmp/chrome-command-line'
Phone 2: MotoG with Android 4.4.4
This is a bit trickier. It turned out that Chrome actually reads the switches from /data/local/chrome-command-line (not in the tmp subdirectory!). Now the issue is that on an unrooted phone you won't have permission to write to this file! So I had to root my phone* and use su to write to the file:
adb shellsuecho "chrome --sync-url" > /data/local/chrome-command-line
*Rooting an Android phone is actually very easy and takes only a few minutes. There are a number of one click apps for rooting your phone (e.g. KingoRoot). For the case of MotoG, I had to do a few more steps to root, following this)