This is the exact same CL as in http://codereview.chromium.org/7570001 .

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 905 matching lines @@
 IPC_MESSAGE_ROUTED0(ViewMsg_CopyToFindPboard)
 #endif
 IPC_MESSAGE_ROUTED0(ViewMsg_Paste)
 // Replaces the selected region or a word around the cursor with the
 // specified string.
 IPC_MESSAGE_ROUTED1(ViewMsg_Replace,
                     string16)
 IPC_MESSAGE_ROUTED0(ViewMsg_Delete)
 IPC_MESSAGE_ROUTED0(ViewMsg_SelectAll)
 
+// Requests the renderer to select the region between two points.
+IPC_MESSAGE_ROUTED2(ViewMsg_SelectRange,
+                    gfx::Point /* start */,
+                    gfx::Point /* end */)
+
 // Copies the image at location x, y to the clipboard (if there indeed is an
 // image at that location).
 IPC_MESSAGE_ROUTED2(ViewMsg_CopyImageAt,
                     int /* x */,
                     int /* y */)
 
 // Tells the renderer to perform the given action on the media player
 // located at the given point.
 IPC_MESSAGE_ROUTED2(ViewMsg_MediaPlayerActionAt,
                     gfx::Point, /* location */
@@ skipping 768 matching lines @@
 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 */,
                     WebKit::WebTextDirection /* text direction hint */)
 
 // Notification that the text selection has changed.
-IPC_MESSAGE_ROUTED2(ViewHostMsg_SelectionChanged,
+IPC_MESSAGE_ROUTED4(ViewHostMsg_SelectionChanged,
                     std::string /* currently selected text */,
-                    ui::Range /* selection range */)
+                    ui::Range /* selection range */,
+                    gfx::Point,
+                    gfx::Point /* visual end points of selection */)
 
 // Asks the browser to display the file chooser.  The result is returned in a
 // ViewHost_RunFileChooserResponse message.
 IPC_MESSAGE_ROUTED1(ViewHostMsg_RunFileChooser,
                     ViewHostMsg_RunFileChooser_Params)
 
 // Asks the browser to enumerate a directory.  This is equivalent to running
 // the file chooser in directory-enumeration mode and having the user select
 // the given directory.  The result is returned in a
 // ViewMsg_EnumerateDirectoryResponse message.
@@ skipping 306 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 */)