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

chrome/browser/renderer_host/render_widget_host_view_win.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/renderer_host/render_widget_host_view_win.h"
 
 #include <algorithm>
 
 #include "base/command_line.h"
 #include "base/i18n/rtl.h"
@@ skipping 746 matching lines @@
   CHECK(!animate);
 
   SkColor overlay_color = color ? *color : 0;
   if (overlay_color_ == overlay_color)
     return;
   overlay_color_ = overlay_color;
 
   InvalidateRect(NULL, FALSE);
 }
 
+void RenderWidgetHostViewWin::UnhandledWheelEvent(
+    const WebKit::WebMouseWheelEvent& event) {
+}
+
+void RenderWidgetHostViewWin::SetHasHorizontalScrollbar(
+    bool has_horizontal_scrollbar) {
+}
+
+void RenderWidgetHostViewWin::SetScrollOffsetPinning(
+    bool is_pinned_to_left, bool is_pinned_to_right) {
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 // RenderWidgetHostViewWin, private:
 
 LRESULT RenderWidgetHostViewWin::OnCreate(CREATESTRUCT* create_struct) {
   // Call the WM_INPUTLANGCHANGE message handler to initialize the input locale
   // of a browser process.
   OnInputLangChange(0, 0);
   // Marks that window as supporting mouse-wheel messages rerouting so it is
   // scrolled when under the mouse pointer even if inactive.
   props_.push_back(views::SetWindowSupportsRerouteMouseWheel(m_hWnd));
@@ skipping 1050 matching lines @@
                                                       DWORD ex_style) {
   parent_hwnd_ = parent_hwnd;
   Create(parent_hwnd_, NULL, NULL, WS_POPUP, ex_style);
   MoveWindow(pos.x(), pos.y(), pos.width(), pos.height(), TRUE);
   // To show tooltip on popup window.(e.g. title in <select>)
   // Popups default to showing, which means |DidBecomeSelected()| isn't invoked.
   // Ensure the tooltip is created otherwise tooltips are never shown.
   EnsureTooltip();
   ShowWindow(IsActivatable() ? SW_SHOW : SW_SHOWNA);
 }