ChangeScreen2: Click anywhere in path column to open file

Instead of requiring a precise click on the path name itself, accept
the entire path column as the click target.  This allows users to hit
a much larger area, which is easier on short file names like 'README'
or 'BUCK'.

Change-Id: I071c6394a33d08eba9b8ce252e92690106e8a743

gerrit-gwtui/src/main/java/com/google/gerrit/client/change/FileTable.java

@@ -81,6 +81,7 @@ class FileTable extends FlowPanel {
 
   private static final String REVIEWED;
   private static final String OPEN;
+  private static final int C_PATH = 3;
   private static final HyperlinkImpl link = GWT.create(HyperlinkImpl.class);
 
   static {
@@ -307,6 +308,15 @@ class FileTable extends FlowPanel {
         Gerrit.display(url(list.get(row - 1)));
       }
     }
+
+    @Override
+    protected void onCellSingleClick(int row, int column) {
+      if (column == C_PATH) {
+        onOpenRow(row);
+      } else {
+        super.onCellSingleClick(row, column);
+      }
+    }
   }
 
   private final class DisplayCommand implements RepeatingCommand {