content: change SetTooltipText to use string16

content/common/view_messages.h

 // 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.
 
 // IPC messages for page rendering.
 // Multiply-included message file, hence no include guard.
 
 #include "base/process.h"
 #include "base/shared_memory.h"
 #include "content/common/common_param_traits.h"
@@ skipping 1689 matching lines @@
 
 // Returns WebScreenInfo corresponding to the view.
 // TODO(shess): Provide a mapping from reply_msg->routing_id() to
 // HWND so that we can eliminate the NativeViewId parameter.
 IPC_SYNC_MESSAGE_ROUTED1_1(ViewHostMsg_GetScreenInfo,
                            gfx::NativeViewId /* view */,
                            WebKit::WebScreenInfo /* results */)
 
 // Send the tooltip text for the current mouse position to the browser.
 IPC_MESSAGE_ROUTED2(ViewHostMsg_SetTooltipText,
-                    std::wstring /* tooltip text string */,
+                    string16 /* tooltip text string */,
                     WebKit::WebTextDirection /* text direction hint */)
 
 // Notification that the text selection has changed.
 IPC_MESSAGE_ROUTED2(ViewHostMsg_SelectionChanged,
                     std::string /* currently selected text */,
                     ui::Range /* selection range */)
 
 // Asks the browser to display the file chooser.  The result is returned in a
 // ViewHost_RunFileChooserResponse message.
 IPC_MESSAGE_ROUTED1(ViewHostMsg_RunFileChooser,
@@ skipping 312 matching lines @@
                     int32 /* complete status */)
 
 // Request updated information about the client firewall traversal policy.
 // Will result in a ViewMsg_UpdateRemoteAccessClientFirewallTraversal message
 // being sent back.
 IPC_MESSAGE_ROUTED0(ViewHostMsg_RequestRemoteAccessClientFirewallTraversal)
 
 // Notifies the browser of an event occurring in the media pipeline.
 IPC_MESSAGE_CONTROL1(ViewHostMsg_MediaLogEvent,
                      media::MediaLogEvent /* event */)