Add Android AX functions to set the value and selection of a text field.

content/common/accessibility_messages.h

Index: content/common/accessibility_messages.h
diff --git a/content/common/accessibility_messages.h b/content/common/accessibility_messages.h
index 5abf149303d45bf183ef250ee99abae830096660..13b820454a3fe5a04b9e03c08777d116510cdccb 100644
--- a/content/common/accessibility_messages.h
+++ b/content/common/accessibility_messages.h
@@ -122,6 +122,12 @@ IPC_MESSAGE_ROUTED3(AccessibilityMsg_SetTextSelection,
                     int /* New start offset */,
                     int /* New end offset */)
 
+// Relay a request from assistive technology to set the value of an
+// editable text element.
+IPC_MESSAGE_ROUTED2(AccessibilityMsg_SetValue,
+                    int /* object id */,
+                    base::string16 /* Value */)
+
 // Determine the accessibility object under a given point and reply with
 // a AccessibilityHostMsg_HitTestResult with the same id.
 IPC_MESSAGE_ROUTED1(AccessibilityMsg_HitTest,