Bug 792652 - IToplevelProtocol refactoring (r=dvander)

Currently toplevel protocols inherit from both IProtocolManager<IProtocol>
and IToplevelProtocol. This change makes IToplevelProtocol inherit from
IProtocol, so now toplevel protocols only inherit from
IToplevelProtocol.

ipc/glue/ProtocolUtils.h

@@ -176,7 +176,7 @@ class Endpoint;
  * IToplevelProtocol tracks all top-level protocol actors created from
  * this protocol actor.
  */
-class IToplevelProtocol
+class IToplevelProtocol : public IProtocol
 {
     template<class PFooSide> friend class Endpoint;
 

ipc/ipdl/ipdl/lower.py

@@ -2809,10 +2809,13 @@ class _GenerateProtocolActorCode(ipdl.ast.Visitor):
             CppDirective('include', '"'+ p.channelHeaderFile() +'"'),
             Whitespace.NL ])
 
-        optinherits = []
+        inherits = []
         if ptype.isToplevel():
-            optinherits.append(Inherit(p.openedProtocolInterfaceType(),
-                                      viz='public'))
+            inherits.append(Inherit(p.openedProtocolInterfaceType(),
+                                    viz='public'))
+        else:
+            inherits.append(Inherit(p.managerInterfaceType(), viz='public'))
+
         if ptype.isToplevel() and self.side is 'parent':
             self.hdrfile.addthings([
                     _makeForwardDeclForQClass('nsIFile', []),
@@ -2821,8 +2824,7 @@ class _GenerateProtocolActorCode(ipdl.ast.Visitor):
 
         self.cls = Class(
             self.clsname,
-            inherits=[ Inherit(p.managerInterfaceType(), viz='public') ] +
-            optinherits,
+            inherits=inherits,
             abstract=True)
 
         bridgeActorsCreated = ProcessGraph.bridgeEndpointsOf(ptype, self.side)