Do not attempt to open a channel to a plugin in Plugin Data Remover if there are no plugins availab…

content/browser/plugin_data_remover_impl.cc

 // Copyright (c) 2012 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 "content/browser/plugin_data_remover_impl.h"
 
 #include <limits>
 
 #include "base/bind.h"
 #include "base/metrics/histogram.h"
@@ skipping 73 matching lines @@
         base::TimeDelta::FromMilliseconds(kRemovalTimeoutMs));
   }
 
   void InitOnIOThread(const std::string& mime_type) {
     PluginServiceImpl* plugin_service = PluginServiceImpl::GetInstance();
 
     // Get the plugin file path.
     std::vector<WebPluginInfo> plugins;
     plugin_service->GetPluginInfoArray(
         GURL(), mime_type, false, &plugins, NULL);
-    base::FilePath plugin_path;
-    if (!plugins.empty())  // May be empty for some tests.
-      plugin_path = plugins[0].path;
+
+    if (plugins.empty()) {
+      // May be empty for some tests and on the CrOS login OOBE screen.
+      OnTimeout();

[Bernhard Bauer, 2015/05/20 21:48:34]

We should probably call this method OnError() now.

[Will Harris, 2015/05/20 21:52:12]

I tried calling OnError() first, but it prints a scary error "Couldn't open
plugin channel" which isn't really an error, since having no plugins is not an
error... so I went with OnTimeout() without setting is_removing_ which prints
nothing.  WDYT?

[Bernhard Bauer, 2015/05/20 21:55:03]

Oh, durr. We really only need SignalDone(), so I guess that's what we should
call.

[Will Harris, 2015/05/20 22:02:59]

yes. good plan.

+      return;
+    }
+    base::FilePath plugin_path = plugins[0].path;
 
     DCHECK_CURRENTLY_ON(BrowserThread::IO);
     remove_start_time_ = base::Time::Now();
     is_removing_ = true;
     // Balanced in On[Ppapi]ChannelOpened or OnError. Exactly one them will
     // eventually be called, so we need to keep this object around until then.
     AddRef();
 
     PepperPluginInfo* pepper_info =
         plugin_service->GetRegisteredPpapiPluginInfo(plugin_path);
@@ skipping 197 matching lines @@
 
 base::WaitableEvent* PluginDataRemoverImpl::StartRemoving(
     base::Time begin_time) {
   DCHECK(!context_.get());
   context_ = new Context(begin_time, browser_context_);
   context_->Init(mime_type_);
   return context_->event();
 }
 
 }  // namespace content