Proxy PPB_Var, fix o-o-p string var id tracking.

ppapi/proxy/plugin_var_serialization_rules.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 "ppapi/proxy/plugin_var_serialization_rules.h"
 
 #include "base/logging.h"
 #include "ppapi/proxy/plugin_dispatcher.h"
 #include "ppapi/proxy/plugin_var_tracker.h"
 
 namespace pp {
 namespace proxy {
 
 PluginVarSerializationRules::PluginVarSerializationRules()
     : var_tracker_(PluginVarTracker::GetInstance()) {
 }
 
 PluginVarSerializationRules::~PluginVarSerializationRules() {
 }
 
 PP_Var PluginVarSerializationRules::SendCallerOwned(const PP_Var& var,
                                                     std::string* str_val) {
   // Objects need special translations to get the IDs valid in the host.
   if (var.type == PP_VARTYPE_OBJECT)
     return var_tracker_->GetHostObject(var);
 
-  // Nothing to do since we manage the refcount, other than retrieve the string
-  // to use for IPC.
-  if (var.type == PP_VARTYPE_STRING)
-    *str_val = var_tracker_->GetString(var);
+  // Retrieve the string to use for IPC.
+  if (var.type == PP_VARTYPE_STRING) {
+    const std::string* var_string = var_tracker_->GetExistingString(var);
+    if (var_string)
+      *str_val = *var_string;
+    else
+      NOTREACHED() << "Trying to send unknown string over IPC.";
+  }
   return var;
 }
 
 PP_Var PluginVarSerializationRules::BeginReceiveCallerOwned(
     const PP_Var& var,
     const std::string* str_val,
     Dispatcher* dispatcher) {
   if (var.type == PP_VARTYPE_STRING) {
     // Convert the string to the context of the current process.
     PP_Var ret;
@@ skipping 71 matching lines @@
   // The plugin maintains one ref count in the browser on behalf of the
   // entire ref count in the plugin. When the plugin refcount goes to 0, it
   // will call the browser to deref the object. This is why in example 2
   // transferring the object ref to the browser involves no net change in the
   // browser's refcount.
 
   // Objects need special translations to get the IDs valid in the host.
   if (var.type == PP_VARTYPE_OBJECT)
     return var_tracker_->GetHostObject(var);
 
-  if (var.type == PP_VARTYPE_STRING)
-    *str_val = var_tracker_->GetString(var);
+  if (var.type == PP_VARTYPE_STRING) {
+    const std::string* var_string = var_tracker_->GetExistingString(var);
+    if (var_string)
+      *str_val = *var_string;
+    else
+      NOTREACHED() << "Trying to send unknown string over IPC.";
+  }
   return var;
 }
 
 void PluginVarSerializationRules::EndSendPassRef(const PP_Var& var,
                                                  Dispatcher* dispatcher) {
   // See BeginSendPassRef for an example of why we release our ref here.
   // The var we have in our inner class has been converted to a host object
   // by BeginSendPassRef. This means it's not a normal var valid in the plugin,
   // so we need to use the special ReleaseHostObject.
   if (var.type == PP_VARTYPE_OBJECT) {
     var_tracker_->ReleaseHostObject(
         static_cast<PluginDispatcher*>(dispatcher), var);
   }
 }
 
 void PluginVarSerializationRules::ReleaseObjectRef(const PP_Var& var) {
   var_tracker_->Release(var);
 }
 
 }  // namespace proxy
 }  // namespace pp