nsig solver: solve with js instead of v8

[oSumAtrIX]

The challenge test passes. I replaced usages of v8s provider and made the dependency compile only. project compiles and works fine over the system webview.

Considerations:

• Availability of WebView on Android
• Old Android/WebView version compatibility (I only tested on Android 13)
• The minSdkVersion had to be set to 26 so that the webview is available
• YouTube player script could theoretically be cached so that it isn't reevaluated everytime. Less relevant for this PR but slight optimization possible. State management would be interesting though.

[oSumAtrIX]

recommended

[yuliskov]

Thanks for the efforts, friend. Why "The minSdkVersion had to be set to 26 so that the webview is available"?

[oSumAtrIX]

AndroidX sets this https://android.googlesource.com/platform/frameworks/support/+/3bb1f317d9f24720d1694128761732b35d3ed177/javascriptengine/javascriptengine/build.gradle#49

[oSumAtrIX]

In specific there is the ability to override:

    Suggestion: use a compatible library with a minSdk of at most 17,
           or increase this project's minSdk version to at least 26,
          or use tools:overrideLibrary="androidx.javascriptengine" to force usage (may lead to runtime failures)

But I haven't tried that, not sure if its a good idea.

[oSumAtrIX]

The alternative is to not rely on androidx and just use the minimum APIs

[yuliskov]

Got it. This looks like a good solution for API 26+, but the standalone V8 is still needed for older devices and for cases where the JavaScript Sandbox service is not supported.

[oSumAtrIX]

WebView itself is available since SDK version 1. So it should be possible to use it in any Android version. The sandbox is also not strictly required; it's provided to isolate YouTube's proprietary VM from the main process as an optional security consideration. I assume V8 does this implicitly.

[oSumAtrIX]

I also noticed cronet, however the only line that actually makes use of cronet in MediaServiceCore is actually commented out:

// addCronetInterceptor(builder)

We can therefore reduce the size even more by removing cronet

[yuliskov]

Got it. Let me know if test this code on old api (e.g. 19)