Adds selection expansion support for Contextual Search.

content/common/input_messages.h

Index: content/common/input_messages.h
diff --git a/content/common/input_messages.h b/content/common/input_messages.h
index ea76042e791e81a7e539895dffc457a95ed7d306..613b4cd9170b7dc7a17eefee9f2b7081701f0a45 100644
--- a/content/common/input_messages.h
+++ b/content/common/input_messages.h
@@ -214,6 +214,12 @@ IPC_MESSAGE_ROUTED2(InputMsg_SelectRange,
                     gfx::Point /* base */,
                     gfx::Point /* extent */)
 
+// Sent by the browser to ask the renderer to expand the selection
+// by the given amounts.
+IPC_MESSAGE_ROUTED2(InputMsg_ExpandSelectionByCharacterOffset,
+                    int /* start_adjust*/,
+                    int /* end_adjust */)
+
 // Requests the renderer to move the selection extent point to a new position.
 // Expects a MoveRangeSelectionExtent_ACK message when finished.
 IPC_MESSAGE_ROUTED1(InputMsg_MoveRangeSelectionExtent,