Add title attribute to tab-search-item title

This change makes URL title fully visible when mouse over it

Bug: 1099917
Change-Id: I306711584fc1ed139a9b925378f27e477ce6430c
Reviewed-on: https://chrome-internal-review.googlesource.com/c/chrome/browser/resources/tab_search/+/3300861Reviewed-by: Tom Lukaszewicz <tluk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#819620}

chrome/browser/resources/tab_search_merge/tab_search_item.html

@@ -63,7 +63,7 @@
 
 <div class="favicon" style="background-image:[[faviconUrl_(data)]]"></div>
 <div class="text-container">
-  <div id="primaryText"></div>
+  <div id="primaryText" title="[[data.title]]"></div>
   <div id="secondaryText"></div>
 </div>
 <div class="button-container">