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..e8ba6f5ca9b38b0d823efb1814d2eebe8f658409 100644
--- a/ppapi/proxy/serialized_structs.h
+++ b/ppapi/proxy/serialized_structs.h
@@ -139,6 +139,17 @@ 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_number(0) {}
+  CompletedBrowserResourceHosts(int sequence_number_param,
+                                const std::vector<int>& host_ids_param)
+      : sequence_number(sequence_number_param), host_ids(host_ids_param) {}
+  int sequence_number;
+  std::vector<int> host_ids;
+};
+
 }  // namespace proxy
 }  // namespace ppapi