Pass Surface ID namespace to renderer compositors.

content/common/view_messages.h

Index: content/common/view_messages.h
diff --git a/content/common/view_messages.h b/content/common/view_messages.h
index 3a0af198eeae32e0ccff2703c7cb5a3bf3c4d3dc..bb688eb72ca3c8493e4bb32d7cf4e68435f300ee 100644
--- a/content/common/view_messages.h
+++ b/content/common/view_messages.h
@@ -535,6 +535,9 @@ IPC_STRUCT_BEGIN(ViewMsg_New_Params)
 
   // The maximum size to layout the page if auto-resize is enabled.
   IPC_STRUCT_MEMBER(gfx::Size, max_size)
+
+  // Namespace for the compositor to generate surface sequences.
+  IPC_STRUCT_MEMBER(uint32_t, surface_id_namespace)
 IPC_STRUCT_END()
 
 // Messages sent from the browser to the renderer.
@@ -590,8 +593,11 @@ IPC_MESSAGE_CONTROL1(ViewMsg_New,
 
 // Reply in response to ViewHostMsg_ShowView or ViewHostMsg_ShowWidget.
 // similar to the new command, but used when the renderer created a view
-// first, and we need to update it.
-IPC_MESSAGE_ROUTED0(ViewMsg_CreatingNew_ACK)
+// first, and we need to update it. |surface_id_namespace| provides a
+// namespace for the RenderWidget's compositor to use to issue surface
+// sequences.
+IPC_MESSAGE_ROUTED1(ViewMsg_CreatingNew_ACK,
+                    uint32_t /* surface_id_namespace */)
 
 // Sends updated preferences to the renderer.
 IPC_MESSAGE_ROUTED1(ViewMsg_SetRendererPrefs,
@@ -981,6 +987,11 @@ IPC_MESSAGE_ROUTED2(ViewMsg_ReclaimCompositorResources,
                     uint32 /* output_surface_id */,
                     cc::CompositorFrameAck /* ack */)
 
+// Sent by browser to give renderer compositor a new namespace ID for any
+// SurfaceSequences it has to create.
+IPC_MESSAGE_ROUTED1(ViewMsg_UpdateSurfaceIdNamespace,
+                    uint32_t /* surface_id_namespace */)
+
 IPC_MESSAGE_ROUTED0(ViewMsg_SelectWordAroundCaret)
 
 // Sent by the browser to ask the renderer to redraw.