Add 'd' shortcut to open download dialog

Pressing the 'd' key in change view now opens the download dialog.

Bug: Issue 4523
Change-Id: I9feb8334f1dc3a85261d77af9f7b9e3cdcf00517

polygerrit-ui/app/elements/change/gr-change-view/gr-change-view.js

@@ -488,6 +488,10 @@
             this._openReplyDialog();
           }
           break;
+        case 68: // 'd'
+          e.preventDefault();
+          this.$.downloadOverlay.open();
+          break;
         case 82: // 'r'
           if (e.shiftKey) {
             e.preventDefault();

polygerrit-ui/app/elements/change/gr-change-view/gr-change-view_test.html

@@ -109,6 +109,13 @@ limitations under the License.
         // 'shift + R'
         MockInteractions.pressAndReleaseKeyOn(element, 82, 'shift');
       });
+
+      test('d should open download overlay', function() {
+        var stub = sinon.stub(element.$.downloadOverlay, 'open');
+        MockInteractions.pressAndReleaseKeyOn(element, 68); // 'd'
+        assert.isTrue(stub.called);
+        stub.restore();
+      });
     });
 
     test('reply button has updated count when there are drafts', function() {

polygerrit-ui/app/elements/core/gr-keyboard-shortcuts-dialog/gr-keyboard-shortcuts-dialog.html

@@ -157,6 +157,10 @@ limitations under the License.
             <td><span class="key">a</span></td>
             <td>Open reply dialog to publish comments and add reviewers</td>
           </tr>
+          <tr>
+            <td><span class="key">d</span></td>
+            <td>Open download overlay</td>
+          </tr>
           <tr>
             <td></td><td class="header">File list</td>
           </tr>