Add basic versioning check to Chromoting's plugin/JS code.

remoting/client/plugin/chromoting_scriptable_object.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "remoting/client/plugin/chromoting_scriptable_object.h"
 
 #include "base/logging.h"
 #include "base/stringprintf.h"
 #include "ppapi/cpp/var.h"
 #include "remoting/client/client_config.h"
 #include "remoting/client/chromoting_stats.h"
 #include "remoting/client/plugin/chromoting_instance.h"
 #include "remoting/client/plugin/pepper_xmpp_proxy.h"
 
 using pp::Var;
 
 namespace remoting {
 
 namespace {
 
+const char kApiVersionAttribute[] = "apiVersion";
+const char kApiMinVersionAttribute[] = "apiMinVersion";
 const char kConnectionInfoUpdate[] = "connectionInfoUpdate";
 const char kDebugInfo[] = "debugInfo";
 const char kDesktopHeight[] = "desktopHeight";
 const char kDesktopWidth[] = "desktopWidth";
 const char kDesktopSizeUpdate[] = "desktopSizeUpdate";
 const char kLoginChallenge[] = "loginChallenge";
 const char kSendIq[] = "sendIq";
 const char kQualityAttribute[] = "quality";
 const char kStatusAttribute[] = "status";
 const char kVideoBandwidthAttribute[] = "videoBandwidth";
@@ skipping 10 matching lines @@
     : instance_(instance) {
 }
 
 ChromotingScriptableObject::~ChromotingScriptableObject() {
 }
 
 void ChromotingScriptableObject::Init() {
   // Property addition order should match the interface description at the
   // top of chromoting_scriptable_object.h.
 
+  // Plugin API version.
+  // This should be incremented whenever the API interface changes.
+  AddAttribute(kApiVersionAttribute, Var(1));
+
+  // This should be updated whenever we remove support for an older version
+  // of the API.
+  AddAttribute(kApiMinVersionAttribute, Var(1));
+
   // Connection status.
   AddAttribute(kStatusAttribute, Var(STATUS_UNKNOWN));
 
   // Connection status values.
   AddAttribute("STATUS_UNKNOWN", Var(STATUS_UNKNOWN));
   AddAttribute("STATUS_CONNECTING", Var(STATUS_CONNECTING));
   AddAttribute("STATUS_INITIALIZING", Var(STATUS_INITIALIZING));
   AddAttribute("STATUS_CONNECTED", Var(STATUS_CONNECTED));
   AddAttribute("STATUS_CLOSED", Var(STATUS_CLOSED));
   AddAttribute("STATUS_FAILED", Var(STATUS_FAILED));
@@ skipping 403 matching lines @@
     *exception = Var("response_xml must be a string.");
     return Var();
   }
 
   xmpp_proxy_->OnIq(args[0].AsString());
 
   return Var();
 }
 
 }  // namespace remoting