[SendTabToSelf] Added logic to display an infobar for the feature.

This CL is one of many to come. It covers:
* Creation of the infobar from the SendTabToSelfInfoBarController
* Plumbed the call to create the infobar to the native code.
* Open the link when user taps on the link

In follow-up CLs, the following will be done:
* Instantiate the InfobarController in the ChromeActivity
* Listen for Model changes in the Controller


Bug: 949233,963193
Change-Id: I5df1359debb5f0f35c32c2df3b691bf9129cdeb8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1604406
Reviewed-by: Tommy Nyquist <nyquist@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Mikel Astiz <mastiz@chromium.org>
Reviewed-by: sebsg <sebsg@chromium.org>
Reviewed-by: Jeffrey Cohen <jeffreycohen@chromium.org>
Reviewed-by: Matthew Jones <mdjones@chromium.org>
Commit-Queue: Tanya Gupta <tgupta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#660854}
const GURL& SendTabToSelfEntry::GetURL() const {
  return url_;
}

const GURL& SendTabToSelfEntry::GetURL() const {
  return url_;
}
