Correct me if I'm wrong, but it looks like other browsers are free to implement the "pepper" API as well. It seems as though they are not saying "we're only supporting Chrome". They are saying "Chrome is the only browser that has implemented Pepper so far, and we're only supporting Pepper on Linux".
> Because of this work, Adobe has been able to partner with Google in providing a “Pepper” implementation of Flash Player for all x86/64 platforms supported by the Google Chrome browser. Google will begin distributing this new Pepper-based Flash Player as part of Chrome on all platforms, including Linux, later this year.
It says that the plug-in will be bundled with Chrome, and Adobe have said they won't be releasing more Flash players for Linux, but the announcement does not even hint whether a stand-alone Pepper plug-in will be available from Google. I hope the Chromium blog will clarify this in due course.
I guess Adobe might forbid Google from developing a plug-in, but I don't see why they would want that, seeing as they have been distributing plug-ins for years. If Google could but didn't, that would make them look unsupportive of Chromium.
If the Adobe blog post is correct and the pepper plugin is only distributed with Chrome and isn't open source and part of Chromium then how is another browser going to support it? They'd have to tell you to install Chrome and then open the plugin from within Chrome's installed directory. Pretty ugly solution.
If it's open source and part of Chromium then they can at least take the source out and ship their own, assuming the licensing allows for that and is compatible with their license.
All in all, this sounds like a pretty complex scenario for non-Chrome browser.
Not Chrome, they can't it is not open source. They could switch to Chromium, which could presumably run flash, but it is not clear how you obtain it if only Chrome will distribute it. Presumably they will have to distribute it as they say they will ship security updates, but that is unclear, as Linux flash does not auto update from Adobe.
If I understand things correctly, there are actually two things going on:
1) Adobe is effectively stopping work on Flash for Linux on their end; it's just not worth it to them.
2) Google is going to support Flash for Linux for Chrome specifically. They can do this because they have access to Flash source and because the Pepper version of the plug-in is much more cross-platform than the NPAPI version, so the support effort is not too great. Given that they already ship a modified Flash, not the stock one, it's not that big a difference from what they're already doing.
So I think you're wrong; even if other browsers implemented the Pepper API, they would also need source licenses from Adobe or would be dependent on Google to get the Flash plug-in.