Modify anchors to use dynamically-generated relative links

Because the gr-app.html payload may be served from a CDN,
relative links will be resolved based on the CDN host, not
the document at load time. Defer to having them resolve after
the html is loaded.

Change-Id: I8bf971776b2b308f8acd3bc3404b0853f853cd6f

polygerrit-ui/app/elements/core/gr-account-dropdown/gr-account-dropdown.html

@@ -82,8 +82,8 @@ limitations under the License.
               <div>[[account.email]]</div>
             </div>
           </li>
-          <li><a href="/switch-account">Switch account</a></li>
-          <li><a href="/logout">Sign out</a></li>
+          <li><a href$="[[_computeRelativeURL('/switch-account')]]">Switch account</a></li>
+          <li><a href$="[[_computeRelativeURL('/logout')]]">Sign out</a></li>
         </ul>
       </div>
     </iron-dropdown>

polygerrit-ui/app/elements/core/gr-account-dropdown/gr-account-dropdown.js

@@ -31,5 +31,9 @@
     _showDropdownTapHandler: function(e) {
       this.$.dropdown.open();
     },
+
+    _computeRelativeURL: function(path) {
+      return '//' + window.location.host + path;
+    },
   });
 })();

polygerrit-ui/app/elements/core/gr-main-header/gr-main-header.html

@@ -130,7 +130,7 @@ limitations under the License.
       }
     </style>
     <nav>
-      <a href="/" class="bigTitle">PolyGerrit</a>
+      <a href$="[[_computeRelativeURL('/')]]" class="bigTitle">PolyGerrit</a>
       <ul class="links">
         <template is="dom-repeat" items="[[_links]]" as="linkGroup">
           <li>
@@ -139,7 +139,7 @@ limitations under the License.
             </span>
             <ul>
               <template is="dom-repeat" items="[[linkGroup.links]]" as="link">
-                <li><a href="[[link.url]]">[[link.name]]</a></li>
+                <li><a href$="[[link.url]]">[[link.name]]</a></li>
               </template>
             </ul>
           </li>
@@ -148,7 +148,7 @@ limitations under the License.
       <div class="rightItems">
         <gr-search-bar value="{{searchQuery}}" role="search"></gr-search-bar>
         <div class="accountContainer" id="accountContainer">
-          <a class="loginButton" href="/login" on-tap="_loginTapHandler">Sign in</a>
+          <a class="loginButton" href$="[[_computeRelativeURL('/login')]]" on-tap="_loginTapHandler">Sign in</a>
           <gr-account-dropdown account="[[_account]]"></gr-account-dropdown>
         </div>
       </div>

polygerrit-ui/app/elements/core/gr-main-header/gr-main-header.js

@@ -70,6 +70,10 @@
       this._loadAccount();
     },
 
+    _computeRelativeURL: function(path) {
+      return '//' + window.location.host + path;
+    },
+
     _computeLinks: function(defaultLinks, userLinks) {
       var links = defaultLinks.slice();
       if (userLinks && userLinks.length > 0) {