Also, "Network.setCacheDisabled" does not seem to work through the extension chrome.debugger API

As per comment #0 we have tested this issue on reported chrome version 67.0.3396.87  using Windows 7.

Steps:
--------
1. Launched chrome
2. Opened Dev tools and pasted the given code in console.
We have seen error in the console.

@Reporter: As we are unable to reproduce the issue from our end. Could you please review the attached screenshot and confirm if anything being missed here and if possible provide test file.


Thanks! 

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Jeez. That was obviously just a sample. i thought you guys would have testing suites for your core extension APIs. I didn't realize I had to do it for you.

chrome.tabs.query({ active: true }, function (tabs) {
   console.log(`This is how I get the tab id {$tabs[0].id}. Wow!`);
   var tabID = tabs[0].id;
   chrome.debugger.attach({tabId:tabID}, "1.3", function() {
      if (chrome.runtime.lastError) {
         console.log(chrome.runtime.lastError.message);
         return;
      }
      chrome.debugger.sendCommand(
            {tabId: tabID},
            "Network.emulateNetworkConditions",
            {offline: false, latency: 500, downloadThroughput:768000, uploadThroughput: 153600},
                function() {
                    console.log(`Debugger Bandwidth Set to 768000 bytes/sec`);
        });
    
   });
   
});

And then open any internet page, preferably a normal heavy-ish one like https://www.theguardian.com/uk and the debugging tools and look at domcontentloaded and load event timing. Try it a few times. Then set the network throttling to the same rate (7.5 MB/s) in the devtools panel and do the same thing. The times are completely different.

Thank you for providing more feedback. Adding the requester to the cc list.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

There is some kind of problem with the acceptance of the commands in the debugger sendCommand API. It may be related to the recent changes made to the devtools where you allowed multiple debuggers. As I said above, "Network.emulateNetworkConditions" is not working and neither is "Network.setCacheDisabled".

And, by the way, it would be good if the chrome.debugger.sendCommand API sent some sort of confirmation in the form of a JSON object. Otherwise, you can't debug the debugger, if you see what I mean.

And, incidentally, it would make sense if the devtools panel, when you opened it after disabling the cache and throttling the network rate through the chrome.debugger.sendCommand API, showed that the cache was disabled and the network was throttled.

@thomasgallagher: network domain now requires enabling before using emulateNetworkConditions, so send `Network.enable` first.

Great. Thanks for the help. I must have been reading an old version of the protocol and all the Stack Overflow stuff is now out of date. I won't make that mistake again!

Would that also explain the "Network.setCacheDisabled" command not working?