PPAPI: Refactor renderer side of browser host creation

ppapi/proxy/serialized_structs.h

Index: ppapi/proxy/serialized_structs.h
diff --git a/ppapi/proxy/serialized_structs.h b/ppapi/proxy/serialized_structs.h
index f3e114c09fa4fc318de79bb7cc63c7d71688fa15..3d6206876ff73c4db124806398936e55dc4873c4 100644
--- a/ppapi/proxy/serialized_structs.h
+++ b/ppapi/proxy/serialized_structs.h
@@ -139,6 +139,18 @@ typedef HANDLE ImageHandle;
 typedef base::SharedMemoryHandle ImageHandle;
 #endif
 
+// CompletedBrowserResourceHosts contains information about the browser-side
+// hosts for resources that the renderer asked the browser to create.
+struct CompletedBrowserResourceHosts {
+  CompletedBrowserResourceHosts() : sequence_num(0) {}
+  CompletedBrowserResourceHosts(int sequence_num_param,
+                                const std::vector<int>& host_ids_param)
+      : sequence_num(sequence_num_param), host_ids(host_ids_param) {
+  }
+  int sequence_num;
+  std::vector<int> host_ids;
+};
+
 }  // namespace proxy
 }  // namespace ppapi