Merge M58 [WebAPKs] Don't crash if WebAPK starts on page which displays interstitial

Merge M58 [WebAPKs] Don't crash if WebAPK starts on page which displays interstitial

This CL:
- Fixes "launch Chrome" intent to actually launch Chrome instead of Herb Chrome
  Custom Tab.
- Finishes the WebAPK if there is no URL to navigate back to.

BUG=658498
Review-Url: https://codereview.chromium.org/2752133002
Cr-Commit-Position: refs/heads/master@{#457682}
(cherry picked from commit 33060182ee896b89c54ec758ac7fccc372e25c1a)

Review-Url: https://codereview.chromium.org/2789883004 .
Cr-Commit-Position: refs/branch-heads/3029@{#524}
Cr-Branched-From: 939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}
Committed: https://chromium.googlesource.com/chromium/src/+/6db2798ee0ed98e89300a14e10a25cfe2659ff33

[pkotwicz, 2017-04-01 01:29:07]

Description was changed from

==========
Merge M58 [WebAPKs] Don't crash if WebAPK starts on page which displays
interstitial

This CL:
- Fixes "launch Chrome" intent to actually launch Chrome instead of Herb Chrome
  Custom Tab.
- Finishes the WebAPK if there is no URL to navigate back to.

BUG=658498

Review-Url: https://codereview.chromium.org/2752133002
Cr-Commit-Position: refs/heads/master@{#457682}
(cherry picked from commit 33060182ee896b89c54ec758ac7fccc372e25c1a)
==========

to

==========
Merge M58 [WebAPKs] Don't crash if WebAPK starts on page which displays
interstitial

This CL:
- Fixes "launch Chrome" intent to actually launch Chrome instead of Herb Chrome
  Custom Tab.
- Finishes the WebAPK if there is no URL to navigate back to.

BUG=658498

Review-Url: https://codereview.chromium.org/2752133002
Cr-Commit-Position: refs/heads/master@{#457682}
(cherry picked from commit 33060182ee896b89c54ec758ac7fccc372e25c1a)

Review-Url: https://codereview.chromium.org/2789883004 .
Cr-Commit-Position: refs/branch-heads/3029@{#524}
Cr-Branched-From:
939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}
Committed:
https://chromium.googlesource.com/chromium/src/+/6db2798ee0ed98e89300a14e10a2...
==========

[pkotwicz, 2017-04-01 01:29:08]

Committed patchset #1 (id:1) manually as
6db2798ee0ed98e89300a14e10a25cfe2659ff33.