Plumbing for browser process to access text surrounding selection.

content/common/frame_messages.h

 // Copyright 2013 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 interacting with frames.
 // Multiply-included message file, hence no include guard.
 
 #include "content/common/content_export.h"
 #include "content/common/content_param_traits.h"
 #include "content/common/frame_message_enums.h"
@@ skipping 340 matching lines @@
 // Notifies the color chooser client that the user selected a color.
 IPC_MESSAGE_ROUTED2(FrameMsg_DidChooseColorResponse, unsigned, SkColor)
 
 // Notifies the color chooser client that the color chooser has ended.
 IPC_MESSAGE_ROUTED1(FrameMsg_DidEndColorChooser, unsigned)
 
 // Notifies the corresponding RenderFrameProxy object to replace itself with the
 // RenderFrame object it is associated with.
 IPC_MESSAGE_ROUTED0(FrameMsg_DeleteProxy)
 
+// Request the text surrounding the selection with a |max_length|. The response
+// will be sent via FrameHostMsg_TextSurroundingSelectionResponse.
+IPC_MESSAGE_ROUTED1(FrameMsg_TextSurroundingSelectionRequest,
+                    size_t /* max_length */)
+
 // -----------------------------------------------------------------------------
 // Messages sent from the renderer to the browser.
 
 // Blink and JavaScript error messages to log to the console
 // or debugger UI.
 IPC_MESSAGE_ROUTED4(FrameHostMsg_AddMessageToConsole,
                     int32, /* log level */
                     base::string16, /* msg */
                     int32, /* line number */
                     base::string16 /* source id */ )
@@ skipping 229 matching lines @@
                     SkColor /* color */)
 
 // Notifies the browser that media has started/stopped playing.
 IPC_MESSAGE_ROUTED3(FrameHostMsg_MediaPlayingNotification,
                     int64 /* player_cookie, distinguishes instances */,
                     bool /* has_video */,
                     bool /* has_audio */)
 
 IPC_MESSAGE_ROUTED1(FrameHostMsg_MediaPausedNotification,
                     int64 /* player_cookie, distinguishes instances */)
+
+// Response for FrameMsg_TextSurroundingSelectionRequest, |startOffset| and
+// |endOffset| are the offsets of the selection in the returned |content|.
+IPC_MESSAGE_ROUTED3(FrameHostMsg_TextSurroundingSelectionResponse,
+                    base::string16,  /* content */
+                    size_t, /* startOffset */
+                    size_t /* endOffset */)