Move preferred scrollbar style preference change listening from renderer to browser, 2 of 3.

content/common/view_messages.h

 // Copyright (c) 2012 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.
 
 // IPC messages for page rendering.
 // Multiply-included message file, hence no include guard.
 
 #include "base/memory/shared_memory.h"
 #include "base/process/process.h"
 #include "base/strings/string16.h"
@@ skipping 47 matching lines @@
 #include "ui/gfx/point.h"
 #include "ui/gfx/range/range.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/rect_f.h"
 #include "ui/gfx/vector2d.h"
 #include "ui/gfx/vector2d_f.h"
 #include "ui/shell_dialogs/selected_file_info.h"
 
 #if defined(OS_MACOSX)
 #include "content/common/mac/font_descriptor.h"
+#include "third_party/WebKit/public/web/mac/WebScrollbarTheme.h"
 #endif
 
 #undef IPC_MESSAGE_EXPORT
 #define IPC_MESSAGE_EXPORT CONTENT_EXPORT
 
 #define IPC_MESSAGE_START ViewMsgStart
 
 IPC_ENUM_TRAITS(AccessibilityMode)
 IPC_ENUM_TRAITS(ViewMsg_Navigate_Type::Value)
 IPC_ENUM_TRAITS(blink::WebContextMenuData::MediaType)
@@ skipping 1200 matching lines @@
 IPC_MESSAGE_ROUTED1(ViewMsg_ReleaseDisambiguationPopupDIB,
                     TransportDIB::Handle /* DIB handle */)
 
 // Notifies the renderer that a snapshot has been retrieved.
 IPC_MESSAGE_ROUTED3(ViewMsg_WindowSnapshotCompleted,
                     int /* snapshot_id */,
                     gfx::Size /* size */,
                     std::vector<unsigned char> /* png */)
 
 #if defined(OS_MACOSX)
+IPC_ENUM_TRAITS_MAX_VALUE(blink::ScrollerStyle, blink::ScrollerStyleOverlay);
+
 // Notification of a change in scrollbar appearance and/or behavior.
-IPC_MESSAGE_CONTROL4(ViewMsg_UpdateScrollbarTheme,
+IPC_MESSAGE_CONTROL5(ViewMsg_UpdateScrollbarTheme,
                      float /* initial_button_delay */,
                      float /* autoscroll_button_delay */,
                      bool /* jump_on_track_click */,
+                     blink::ScrollerStyle /* preferred_scroller_style */,
                      bool /* redraw */)
 #endif
 
 #if defined(OS_ANDROID)
 // Tells the renderer to suspend/resume the webkit timers.
 IPC_MESSAGE_CONTROL1(ViewMsg_SetWebKitSharedTimersSuspended,
                      bool /* suspend */)
 
 // Sent when the browser wants the bounding boxes of the current find matches.
 //
@@ skipping 1028 matching lines @@
 // synchronously (see crbug.com/120597). This IPC message sends the character
 // bounds after every composition change to always have correct bound info.
 IPC_MESSAGE_ROUTED2(ViewHostMsg_ImeCompositionRangeChanged,
                     gfx::Range /* composition range */,
                     std::vector<gfx::Rect> /* character bounds */)
 #endif
 
 // Adding a new message? Stick to the sort order above: first platform
 // independent ViewMsg, then ifdefs for platform specific ViewMsg, then platform
 // independent ViewHostMsg, then ifdefs for platform specific ViewHostMsg.