The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/dbe1a9621011e05c39f4e78fda6793dcc464f827

commit dbe1a9621011e05c39f4e78fda6793dcc464f827
Author: galinap <galinap@google.com>
Date: Wed Sep 13 14:29:20 2017

[Contextual Suggestions] Use a clean url for contextual suggestion fetch

Before sending a fetch request for suggestions for the current context
to the native side, we want to check if the current URL is valid.

If there is no active tab (which is the case when all tabs are
dismissed), we clear the suggestions.
If the URL is not a HTTP or a HTTP URL, we clear the suggestions.

We also want to make sure that we don't initiate a fetch when the
carousel already has suggestions for the current context. To do this,
we compare if the new URL and the old URL are the same excluding the
fragments.

In all these cases we don't send a request to the native side.
Otherwise, if the URL is a new network URL, we send a request to the
backend.

Bug:  745660 
Change-Id: Iab7680e8e704f3de6fb4ed88be9e26c0fda3deca
Reviewed-on: https://chromium-review.googlesource.com/646326
Commit-Queue: Galia Peycheva <galinap@google.com>
Reviewed-by: Andre Gaschler <gaschler@chromium.org>
Reviewed-by: Nicolas Dossou-Gbété <dgn@chromium.org>
Cr-Commit-Position: refs/heads/master@{#501627}
[modify] https://crrev.com/dbe1a9621011e05c39f4e78fda6793dcc464f827/chrome/android/java/src/org/chromium/chrome/browser/suggestions/SuggestionsCarousel.java