Make 'c', 'r' in a patch view open a new comment editor

Like enter, these open a new comment editor for the current line.

Signed-off-by: Shawn O. Pearce <sop@google.com>

src/main/java/com/google/gerrit/client/patches/AbstractPatchContentTable.java

@@ -107,6 +107,17 @@ public abstract class AbstractPatchContentTable extends FancyFlexTable<Object> {
         case KeyboardListener.KEY_UP:
         case KeyboardListener.KEY_DOWN:
           return false;
+
+        case 'c':
+        case 'r':
+          for (int row = getCurrentRow(); 0 <= row; row--) {
+            final Object item = getRowItem(row);
+            if (!(item instanceof CommentList) && item != null) {
+              onOpenItem(item);
+              break;
+            }
+          }
+          return true;
       }
     }
     return super.onKeyPress(keyCode, modifiers);

src/main/java/com/google/gerrit/client/ui/FancyFlexTable.java

@@ -155,7 +155,7 @@ public abstract class FancyFlexTable<RowItem> extends Composite implements
     }
   }
 
-  private void onOpen() {
+  protected void onOpen() {
     if (0 <= currentRow && currentRow < table.getRowCount()) {
       final RowItem item = getRowItem(currentRow);
       if (item != null) {