Coverity fixes for uninitialized vars

ppapi/native_client/src/shared/ppapi_proxy/plugin_resource_tracker.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 "native_client/src/shared/ppapi_proxy/plugin_resource_tracker.h"
 
 #include <limits>
 #include <set>
 
 #include "base/basictypes.h"
@@ skipping 22 matching lines @@
 
 scoped_refptr<PluginResource> PluginResourceTracker::GetExistingResource(
     PP_Resource res) const {
   ResourceMap::const_iterator result = live_resources_.find(res);
   if (result == live_resources_.end())
     return scoped_refptr<PluginResource>();
   else
     return result->second.resource;
 }
 
-PluginResourceTracker::PluginResourceTracker() {
+PluginResourceTracker::PluginResourceTracker() : last_id_(0) {
 }
 
 void PluginResourceTracker::AddResource(PluginResource* resource,
                                         PP_Resource id,
                                         size_t browser_refcount) {
   // Add the resource with plugin use-count 1.
   live_resources_.insert(
       std::make_pair(id, ResourceAndRefCounts(resource, browser_refcount)));
 }
 
@@ skipping 45 matching lines @@
   // Release all browser references.
   if (res && (browser_refcount > 0)) {
     NaClSrpcChannel* channel = ppapi_proxy::GetMainSrpcChannel();
     PpbCoreRpcClient::ReleaseResourceMultipleTimes(channel, res,
                                                    browser_refcount);
   }
 }
 
 }  // namespace ppapi_proxy