[Android WebView] Propagate Java exceptions from handleJsBeforeUnload.

[Android WebView] Propagate Java exceptions from handleJsBeforeUnload.

WebView applications can throw run-time exceptions within
WebView-callbacks. When such an exception is thrown from either
onJsBeforeUnload, it is not correctly propagated to Android's feedback
mechanism. This is because that callbacks is called through JNI, and the
default way (in Chromium) of handling Java exceptions thrown on the
Java-side of JNI calls is to print the stack trace for the current
exception to the logcat when the JNI call returns to native, and then
intentionally crash in native.

With this CL we avoid the problem of propagating a Java exception back
through JNI and the native stack by posting the WebView-callback (which
can cause the Java exception) as a new task to the current Java Handler.
In that way any Java exception thrown inside the WebView-callback can be
propagated directly up to the Android framework's
UncaughtExceptionHandler which then properly reports the Exception
through the framework's crash reporting mechanism.

BUG=723699
Review-Url: https://codereview.chromium.org/2887173004
Cr-Commit-Position: refs/heads/master@{#472911}
Committed: https://chromium.googlesource.com/chromium/src/+/e49ac49943ad77f452e6a586612b2cfcae8d63ff

[gsennton, 2017-05-18 17:37:19]

gsennton@chromium.org changed reviewers:
+ torne@chromium.org

[gsennton, 2017-05-18 17:37:19]

ptal :)

[Torne, 2017-05-18 18:48:35]

lgtm

[gsennton, 2017-05-18 19:13:48]

The CQ bit was checked by gsennton@chromium.org

[commit-bot: I haz the power, 2017-05-18 19:14:45]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-05-18 20:15:22]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1495134828124560, "parent_rev":
"abf6d850267cf2669a6ed99c8cd690f58dfb2eb2", "commit_rev":
"e49ac49943ad77f452e6a586612b2cfcae8d63ff"}

[commit-bot: I haz the power, 2017-05-18 20:15:33]

Description was changed from

==========
[Android WebView] Propagate Java exceptions from handleJsBeforeUnload.

WebView applications can throw run-time exceptions within
WebView-callbacks. When such an exception is thrown from either
onJsBeforeUnload, it is not correctly propagated to Android's feedback
mechanism. This is because that callbacks is called through JNI, and the
default way (in Chromium) of handling Java exceptions thrown on the
Java-side of JNI calls is to print the stack trace for the current
exception to the logcat when the JNI call returns to native, and then
intentionally crash in native.

With this CL we avoid the problem of propagating a Java exception back
through JNI and the native stack by posting the WebView-callback (which
can cause the Java exception) as a new task to the current Java Handler.
In that way any Java exception thrown inside the WebView-callback can be
propagated directly up to the Android framework's
UncaughtExceptionHandler which then properly reports the Exception
through the framework's crash reporting mechanism.

BUG=723699
==========

to

==========
[Android WebView] Propagate Java exceptions from handleJsBeforeUnload.

WebView applications can throw run-time exceptions within
WebView-callbacks. When such an exception is thrown from either
onJsBeforeUnload, it is not correctly propagated to Android's feedback
mechanism. This is because that callbacks is called through JNI, and the
default way (in Chromium) of handling Java exceptions thrown on the
Java-side of JNI calls is to print the stack trace for the current
exception to the logcat when the JNI call returns to native, and then
intentionally crash in native.

With this CL we avoid the problem of propagating a Java exception back
through JNI and the native stack by posting the WebView-callback (which
can cause the Java exception) as a new task to the current Java Handler.
In that way any Java exception thrown inside the WebView-callback can be
propagated directly up to the Android framework's
UncaughtExceptionHandler which then properly reports the Exception
through the framework's crash reporting mechanism.

BUG=723699

Review-Url: https://codereview.chromium.org/2887173004
Cr-Commit-Position: refs/heads/master@{#472911}
Committed:
https://chromium.googlesource.com/chromium/src/+/e49ac49943ad77f452e6a586612b...
==========

[commit-bot: I haz the power, 2017-05-18 20:15:36]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/e49ac49943ad77f452e6a586612b...