[WebAPKs]: Run WebApkInstaller::OnInstallFinished() for Google Play updates

[WebAPKs]: Run WebApkInstaller::OnInstallFinished() for Google Play updates

This CL:
- fixes bug where WebApkInstaller#updateAsyncFromGooglePlay() was not
calling nativeOnInstallFinished()
- passes callback to GooglePlayWebApkInstallDelegate#installAsync() so that
callback is called only after update completes

Review-Url: https://codereview.chromium.org/2740003002
Cr-Commit-Position: refs/heads/master@{#456589}
(cherry picked from commit 8c81f4b49feeac64da3f1ff1ff2dd58053420247)

BUG=699879
Review-Url: https://codereview.chromium.org/2767643003 .
Cr-Commit-Position: refs/branch-heads/3029@{#339}
Cr-Branched-From: 939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}
Committed: https://chromium.googlesource.com/chromium/src/+/8d34d8a7b1dcccfa8ee2803000d0fab027f9eda0

[pkotwicz, 2017-03-21 19:20:25]

Description was changed from

==========
[WebAPKs]: Run WebApkInstaller::OnInstallFinished() for Google Play updates

This CL:
- fixes bug where WebApkInstaller#updateAsyncFromGooglePlay() was not
calling nativeOnInstallFinished()
- passes callback to GooglePlayWebApkInstallDelegate#installAsync() so that
callback is called only after update completes

Review-Url: https://codereview.chromium.org/2740003002
Cr-Commit-Position: refs/heads/master@{#456589}
(cherry picked from commit 8c81f4b49feeac64da3f1ff1ff2dd58053420247)

BUG=699879
==========

to

==========
[WebAPKs]: Run WebApkInstaller::OnInstallFinished() for Google Play updates

This CL:
- fixes bug where WebApkInstaller#updateAsyncFromGooglePlay() was not
calling nativeOnInstallFinished()
- passes callback to GooglePlayWebApkInstallDelegate#installAsync() so that
callback is called only after update completes

Review-Url: https://codereview.chromium.org/2740003002
Cr-Commit-Position: refs/heads/master@{#456589}
(cherry picked from commit 8c81f4b49feeac64da3f1ff1ff2dd58053420247)

BUG=699879

Review-Url: https://codereview.chromium.org/2767643003 .
Cr-Commit-Position: refs/branch-heads/3029@{#339}
Cr-Branched-From:
939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}
Committed:
https://chromium.googlesource.com/chromium/src/+/8d34d8a7b1dcccfa8ee2803000d0...
==========

[pkotwicz, 2017-03-21 19:20:27]

Committed patchset #1 (id:1) manually as
8d34d8a7b1dcccfa8ee2803000d0fab027f9eda0.