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Angular 2 Application reacting very slowly only while Chrome DevTools is open

My Angular 2 Application is slow to respond (1-5 seconds) to key input, button clicks, tabbing across inputs, etc. only when Chrome Developer Tools is open. Material 2 animations also become slow and choppy.
I've been developing this application for three months, and use Chrome DevTools every day. This issue cropped up seemingly overnight.
What I know:
I stashed all pending application changes to revert my application to a time when this was not a problem. The issue persisted.
Chrome DevTools doesn't seem to slow down any other application (ie. google inbox, google maps) in the same browser session.
Maddeningly, when I run the DevTools' Timeline "Record" to try to gain visibility into the issue, the issue disappears and the page reacts at normal speed again! I assume this is the best clue that I have, but I don't know the internal workings of DevTools well enough to know how "Timeline Record" changes things.
I've restarted Chrome and deleted all cached data.
Nothing of the sort happens in Firefox or IE when I open the Developer tools in those.
Any recommendations on where to look next would be greatly appreciated!

Final answer:
Remove all breakpoints
Even if they're not getting hit this fixed it for me and got performance back to normal.
May be a bigger issue if you have logging breakpoints - so try deleting those first if you're attached to your breakpoints.
Previous answers:
I came up with a workaround - although still not really figured out what is actually wrong.
I also discovered a bunch of tools I didn't even know existed that I'd skipped over before - they're under More tools.
Start by opening the Performance Monitor. This shows a nice CPU graph isolated for your Chrome tab - the Windows task manager is as useless as it ever was.
This is the behavior I got when choosing a date from mat-calendar. No other logic running - just selecting a date. I removed everything from app-component and just put a mat-calendar and it took ten seconds to change the date!
Other controls are generally fine. I could open dialogs, use combo boxes etc. and nice and fast. But selecting a date gave me this nonsense:
I tried emptying local storage, clearing cache, etc. and then I changed port number for my website. I simply changed dev.example.com:44300 to dev.example.com:44301 - in other words Chrome now thought it was a different website.
This is what it looked like after I switched port number.
I also got the same effect using a reverse proxy server - which put my local machine on the internet - so I could try to duplicate the issue from other machines. I could not.
So hope that helps someone - still no clue what's in the cache for this server that is having such a massive impact on performance. But for sure it's not just my code.
Here's a few other things to try:
Test with --aot flag
This didn't make a difference to me, but good to narrow things down.
Add some controls that don't do anything (as a control)
This way you can find if some specific action or control is causing the slow down. You should of course be able to toggle these instantly.
Just toggle them on and off, hide something.
<mat-radio-group>
<mat-radio-button [value]="false">
bloop
</mat-radio-button>
<mat-radio-button [value]="false">
bloop bloop
</mat-radio-button>
</mat-radio-group>
Enable Rendering debugging options
Make sure you aren't re-rendering the whole page constantly
The rendering option above will show this to some extent, but one thing I like to do is just add a random text box - type in it and if the text subsequently disappears you know that control has been rerendered.
<!-- yes, just a standard text box -->
<input type="text"/>
Just hide things with *ngIf="false"
Hide controls (yours and third party) and see if anything is causing problems.
For me I'm currently suspecting mat-calendar is causing issues - but I'm still thoroughly confused as to why enabling 'Record' makes the problem non existent.

I've fixed the issue, but I'll never know what was causing it. Likely a setting that I had accidentally changed.
I deleted the Chrome App and reinstalled, everything is back to normal. I'm going to leave this question open in case anyone else has this problem or wants to contribute.

It is normal for every web app to run slowly with Chrome dev tools opened.
Especially if you have inspect tab open, that it's like a new page opened in the same time + has animations on any block render.

We had this issue today at a colleagues workstation. Turned out that it was a chrome-extension (don't remember, something with "ghost" in its name). So maybe try out using guest-mode and check whether the issue still occurs. If it doesn't, successively reactivate the extensions to see which one is causing the problems. If it still occurs, follow the other proposed approaches.

Firefox page load event very long

I'm going to try to explain an issue that scratch my head...
When I open this website for the first time after opening Firefox (v43.0.3), the UI freeze during about 20 seconds and I don't undersand why. For example you can see that the background image appear after almost 20 seconds...
So, I used firebug net panel to try to understand where the problem comes from and I notice that the page load event is very long but I can't see any tasks executing during this event.
here is a screenshot of firebug Net Panel
When I open the website with Chrome it works fine, does someone has ever encounter that kind of problem ?
I hope that makes sense, thank you in advance.

You're making 31 requests (according to my NET panel - FireBug) which add to 323ms (at least in my case). Your background image is loading ~1s after. Maybe if you'd try to reorganize all that sprites you're requesting into less files - but it seems fair as loading time for me.

I once had a problem with Firebug itself. I had to turn it off and\or uninstall to get the page load normally on Firefox.
In my case it was an effect of problem between Firebug and Telerik Kendo JS Library.
Maybe you have a problem similar issue.

Thanks for your answers, indeed it seem's to comes from my firefox configuration or addons/plugins.
I use a Firefox pre-configured by my socity, so I installed a portable firefox to try if it works and the website is loading normaly.
Now I just have to find from whitch config or addons/plugins the problem comes from, thanks again !

Why would Chrome take 12 seconds to do an Update Layer Tree?

I have a relatively un-complex ASP.Net application, which occasionally displays an alert message in layer, with a shadow, with a pushbutton to dismiss the notification.
This code has been working fine for years.
Lately, I am getting complaints from users of really slow response. What they experience is that the page is completely unresponsive, and when they click on the [OK] pushbutton nothing happens for a really long time.
When I record a Timeline, I can see the original even which caused a round-trip to the webserver, and I can see the response from the webserver. I can also see all the Javascript code which runs as a result of the response.
As far as the application is concerned, the transaction is over, and, as far as the Javascript is concerned, the transaction is over as well. All we need to do is wait for the user to click the [OK] button and we will dismiss the notification popup.
This is where the "freeze" happens. The [OK] event is not delivered for like 20-30 seconds. What's going on in the meantime? That's why I'm writing:
We see some very short timers fire every once in a while, then we see a quick Recalculate Style call, followed by an Update Layer Tree event.
The Update Layer Tree event takes 10-12 seconds!
Here's the code for the dialog which is going unresponsive because of the Update Layer Tree events The gets displayed first as you see it here, then, if something goes wrong, it may get updated with code similar to showAlert:
Status/error dialog code

See #tiblu's comment for detail on why Chrome would perform Update Layer Tree.
As for taking 12 seconds: does the interaction behave normally in other browsers, for example Firefox or Safari? If your code has been working fine for years as you say and the browser response issues have been popping up recently (> mid-October, 2015) and only in Chrome the issue may not be your code.
There are a number of similar new issues and complaints recently, pointing to the release of Chrome 46. For example: this issue (code.google.com) and this issue (code.google.com).
CPU spikes are responsible for browser unresponsiveness, which you can monitor using Chrome's Task Manager. As for why CPU is spiking and further detail you'll need to follow the issues above and others as they develop.
Apologies for the pseudo-answer, don't currently have the rep to slip this into a comment.

Thanks to all who responded ... I was unable to figure out how to re-install an older version of Chrome, but I did manage to get my hands on a beta version of Chrome 48 (48.0.2564.8), and, to my most pleasant surprise, I am no longer able to reproduce the problem.
Just to be sure, I restored 46 from this morning's BACKUP, and it re-exhibited the issue. After re-installing beta-48, the problem is gone.
Hooray! Well done everyone!

PhoneGap loading although script is running

I am developing a reasonably large application on PhoneGap version 2.8 for Android. The issue that I can't seem to fix or even understand why it is happening is described as follows. When I start the application, initially a white screen is shown, which is completely fine since I undestand that it takes a moment or two to launch cordova. I have added a plugin to the project that puts the application to the background when user clicks "back" button in the "home" view. I can see that my app is still running in the task manager which is all fine and dandy. If I click on the app to bring it to foreground, app returns to foreground but views blank white screen for ~3 seconds, after which my view is rendered. I am wondering if there is any way I could speed up whatever the process is going on. I have noticed that it doesn't happen if my app isn't installed with APK but is run by IDE in debug mode (in which case it runs instantly just like any other normal app), but it still persists, if I click on the app icon in the apps menu.
I know that onDeviceReady event is fired way before the blank screen is gone. I know that some html is added into DOM tree. By the time white screen disappears even my ajax request is back with more data to be displayed on the screen. I know that whatever is, that effect is not because of my scripts being loaded in.
I suspect that this is effect is due to Phonegap taking a moment to restore it's Activity, or WebView to restore (if that makes sense).
I have tested that on different physical devices (Galaxy S2 and S3, HTC One X).
There is alot of optimization still to be done (memory is leaking somewhere, and there seems to be alot of performance issues with older phones eg. HTC One V).
I have tried to show Splashscreen while the white screen is up, but it is hard to estimate, when i should hide it (javascript seems to be running asynchroniously in relation to white screen).
Perhaps anyone would be kind enough to explain what is causing the white screen to be present and what could be done to resolve that issue.
Much obliged,
Erich

how to overcome on unresponsiveness of buttons using Phonegap?

Buttons in my application using Phonegap + Eclipse sometimes don't respond to the onclick event, making the App looks like it's frozen.
If I scroll the page up and down, sometimes they start working, but this can be accepted as a solution to the problem.
I've updated Cordova to version 2.7.0 but I still have the same issue.
Could anyone please help me on this situation?

Don't do much in Click handlers.
It freezes because the main thread is blocked by the click handler. Then everything stops. Do as much as you can on the server.

I use this NoClickDelay
I did end up making some changes to it so that the touch and move worked better. I was finding that if your finger moved even the slightest it did not register the click. I increased the tolerance and it worked fine.
something like
if (Math.abs(e.changedTouches[0].screenX - this.startX) < 30 && Math.abs(e.changedTouches[0].screenY - this.startY) < 30 ) {
this.theCallBack();
}