mac: Only let two-finger-scrolling trigger history if web doesn't swallow gesture

chrome/browser/renderer_host/render_widget_host_view_views.cc

Index: chrome/browser/renderer_host/render_widget_host_view_views.cc
diff --git a/chrome/browser/renderer_host/render_widget_host_view_views.cc b/chrome/browser/renderer_host/render_widget_host_view_views.cc
index 95f5083eb3382ddad2025a39dad7879a91eb621e..510b295e6e64c2ca21f3e46309a90a558ab5b3db 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_views.cc
+++ b/chrome/browser/renderer_host/render_widget_host_view_views.cc
@@ -335,6 +335,18 @@ void RenderWidgetHostViewViews::SetVisuallyDeemphasized(
   // TODO(anicolao)
 }
 
+void RenderWidgetHostViewViews::UnhandledWheelEvent(
+    const WebKit::WebMouseWheelEvent& event) {
+}
+
+void RenderWidgetHostViewViews::SetHasHorizontalScrollbar(
+    bool has_horizontal_scrollbar) {
+}
+
+void RenderWidgetHostViewViews::SetScrollOffsetPinning(
+    bool is_pinned_to_left, bool is_pinned_to_right) {
+}
+
 void RenderWidgetHostViewViews::SelectRect(const gfx::Point& start,
                                            const gfx::Point& end) {
   if (host_)