I think we should increase the priority of this issue, as it causes confusion and inconsistency in using WebView SL. Initially setting it M69.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6f8da54669d46aeb57590068e1bf1991a507897d

commit 6f8da54669d46aeb57590068e1bf1991a507897d
Author: Nate Fischer <ntfschr@chromium.org>
Date: Wed Jun 20 23:27:40 2018

AW: implement getWebChromeClient in support library

This implements getWebChromeClient in the support library glue and
boundary_interfaces, and declares that the APK supports the Feature.

Bug:  853030 
Test: (in support lib) ./gradlew :webkit:connectedAndroidTest
Test: android_webview/tools/run_cts.py (on O device, to verify CTS)
Change-Id: I9e19a017b6bfc05d287c1d8c2c112eea86f65c4f
Reviewed-on: https://chromium-review.googlesource.com/1107273
Commit-Queue: Nate Fischer <ntfschr@chromium.org>
Reviewed-by: Tobias Sargeant <tobiasjs@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569083}
[modify] https://crrev.com/6f8da54669d46aeb57590068e1bf1991a507897d/android_webview/glue/java/src/com/android/webview/chromium/SharedWebViewChromium.java
[modify] https://crrev.com/6f8da54669d46aeb57590068e1bf1991a507897d/android_webview/glue/java/src/com/android/webview/chromium/WebViewChromium.java
[modify] https://crrev.com/6f8da54669d46aeb57590068e1bf1991a507897d/android_webview/support_library/boundary_interfaces/src/org/chromium/support_lib_boundary/WebViewProviderBoundaryInterface.java
[modify] https://crrev.com/6f8da54669d46aeb57590068e1bf1991a507897d/android_webview/support_library/boundary_interfaces/src/org/chromium/support_lib_boundary/util/Features.java
[modify] https://crrev.com/6f8da54669d46aeb57590068e1bf1991a507897d/android_webview/support_library/java/src/org/chromium/support_lib_glue/SupportLibWebViewChromium.java
[modify] https://crrev.com/6f8da54669d46aeb57590068e1bf1991a507897d/android_webview/support_library/java/src/org/chromium/support_lib_glue/SupportLibWebViewChromiumFactory.java

Please add the test verification if applicable.

Bulk edit: marking stale 'fixed' bugs as 'verified' since they don't need verification at this point.

Do we also plan to add WebChromeClientCompat? I think onJsWindowPrint() support will depend on it.

That's actually orthogonal from getWebChromeClient API.

We didn't implement WebChromeClientCompat because, as of today, there are no post-L WebChromeClient APIs (and therefore, there's nothing to implement).

If you want to land new WebChromeClient APIs, you'll want to implement WebChromeClientCompat, following the design of WebViewClientCompat.

Makes sense. Thanks!

Rather than stashing it in WebChromeClient, I'd much prefer a separate callback class, or simply a setter that takes a Callable.

WebChromeClient is consistent with other JS APIs (e.g., onConsoleMessage, onJsAlert). I think this is a reasonable spot.