Expand patchset if patchsetID provided in URL

appengine/chromium_rietveld/new_static/components/cr-issue-patchsets.html

Index: appengine/chromium_rietveld/new_static/components/cr-issue-patchsets.html
diff --git a/appengine/chromium_rietveld/new_static/components/cr-issue-patchsets.html b/appengine/chromium_rietveld/new_static/components/cr-issue-patchsets.html
index 5d753ebd86e2c17b42a8c34e72f82c98ad4343e7..20d423cbf3f7a9949c6bc2135ae6ab129c418a48 100644
--- a/appengine/chromium_rietveld/new_static/components/cr-issue-patchsets.html
+++ b/appengine/chromium_rietveld/new_static/components/cr-issue-patchsets.html
@@ -76,11 +76,19 @@ found in the LICENSE file. -->
                 this.olderPatchsets = null;
                 this.currentPatchset = null;
             },
+            attached: function() {
+                if (window.location.hash.startsWith('#ps')) {
+                  var psId = parseInt(window.location.hash.substring(3));
+                  this.showOlderPatchsets = true;
+                  this.patchsets.forEach(function(patchset) {
+                    patchset.active = (patchset.id == psId);
+                  });
+                }
+            },
             patchsetsChanged: function(oldValue, newValue) {
                 var value = newValue || [];
                 this.olderPatchsets = value.to(-1);
                 this.currentPatchset = value.last();
-                this.showOlderPatchsets = false;
             },
             pluralize: function(text, count) {
                 if (!count)