CL: https://codereview.chromium.org/2338203002

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/03d2b0f7c783a91ffdb37942208ffa4ec79b6fb9

commit 03d2b0f7c783a91ffdb37942208ffa4ec79b6fb9
Author: mgiuca <mgiuca@chromium.org>
Date: Wed Sep 28 01:27:20 2016

Added end-to-end tests for navigator.share.

There are separate tests for pre-Lollipop and post-Lollipop Android
(which run completely different code paths in ShareHelper and exhibit
different behaviour). On pre-Lolliop devices, the post-Lollipop tests
are skipped. On post-Lollipop devices, both sets of tests are run.

Adds some new bits to ShareHelper to facilitate testing.

BUG= 645006 

Review-Url: https://codereview.chromium.org/2338203002
Cr-Commit-Position: refs/heads/master@{#421417}

[modify] https://crrev.com/03d2b0f7c783a91ffdb37942208ffa4ec79b6fb9/chrome/android/BUILD.gn
[modify] https://crrev.com/03d2b0f7c783a91ffdb37942208ffa4ec79b6fb9/chrome/android/java/src/org/chromium/chrome/browser/share/ShareHelper.java
[modify] https://crrev.com/03d2b0f7c783a91ffdb37942208ffa4ec79b6fb9/chrome/android/java_sources.gni
[add] https://crrev.com/03d2b0f7c783a91ffdb37942208ffa4ec79b6fb9/chrome/android/javatests/src/org/chromium/chrome/browser/WebShareTest.java
[add] https://crrev.com/03d2b0f7c783a91ffdb37942208ffa4ec79b6fb9/content/test/data/android/webshare.html