AndroidOverlay implementation using Dialog.

content/common/frame_messages.h

Index: content/common/frame_messages.h
diff --git a/content/common/frame_messages.h b/content/common/frame_messages.h
index fe6c2581d778a4ee9ef005f4268a59d49a781068..03945f3299605608e0d838056f382364c843b327 100644
--- a/content/common/frame_messages.h
+++ b/content/common/frame_messages.h
@@ -889,6 +889,11 @@ IPC_MESSAGE_ROUTED3(FrameMsg_ActivateNearestFindResult,
 // this immediately after a FrameHostMsg_Find_Reply message arrives with
 // final_update set to true).
 IPC_MESSAGE_ROUTED1(FrameMsg_FindMatchRects, int /* current_version */)
+
+// Notify the renderer of our overlay routing token.
+IPC_MESSAGE_ROUTED2(FrameMsg_SetOverlayRoutingToken,
+                    uint64_t /* high */,

[dcheng, 2017/04/03 19:12:40]

Why not just send the base::UnguessableToken directly?

[liberato (no reviews please), 2017/04/04 17:49:29]

because i forgot that it had paramtraits already.  thanks!

+                    uint64_t /* low */)
 #endif
 
 #if BUILDFLAG(USE_EXTERNAL_POPUP_MENU)
@@ -1646,6 +1651,10 @@ IPC_MESSAGE_ROUTED2(FrameHostMsg_GetNearestFindResult_Reply,
                     float /* distance */)
 
 IPC_MESSAGE_ROUTED0(FrameHostMsg_NavigationHandledByEmbedder)
+
+// Request that the host send its overlay routing token for this render frame
+// via SetOverlayRoutingToken.
+IPC_MESSAGE_ROUTED0(FrameHostMsg_RequestOverlayRoutingToken)
 #endif
 
 // Adding a new message? Stick to the sort order above: first platform