Use realpath() to find the path to the extension unpack dir on posix systems.

chrome/browser/utility_process_host.cc

 // Copyright (c) 2009 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 "chrome/browser/utility_process_host.h"
 
 #include "app/app_switches.h"
 #include "app/l10n_util.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/message_loop.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/utility_messages.h"
 #include "ipc/ipc_switches.h"
 
 UtilityProcessHost::UtilityProcessHost(ResourceDispatcherHost* rdh,
                                        Client* client,
                                        ChromeThread::ID client_thread_id)
     : ChildProcessHost(UTILITY_PROCESS, rdh),
       client_(client),
       client_thread_id_(client_thread_id) {
 }
 
 UtilityProcessHost::~UtilityProcessHost() {
 }
 
 bool UtilityProcessHost::StartExtensionUnpacker(const FilePath& extension) {
+  FilePath initial_path = extension.DirName();
+  FilePath real_path;
+
+#if defined(OS_POSIX)
+  if (!file_util::RealPath(initial_path, &real_path)) {
+    real_path = initial_path;
+  }
+#else
+  // TODO(skerner): For windows, we need to expand NTFS junctions.
+  // http://crbug.com/13044
+  real_path = initial_path;
+#endif
+
+  // TODO(skerner): Remove this logging once we understand crbug.com/35198
+  LOG(INFO) << "initial_path: " << initial_path.value();
+  LOG(INFO) << "real_path: " << real_path.value();
+
   // Grant the subprocess access to the entire subdir the extension file is
   // in, so that it can unpack to that dir.
-  if (!StartProcess(extension.DirName()))
+  if (!StartProcess(real_path))
     return false;
 
   Send(new UtilityMsg_UnpackExtension(extension));
   return true;
 }
 
 bool UtilityProcessHost::StartWebResourceUnpacker(const std::string& data) {
   if (!StartProcess(FilePath()))
     return false;
 
@@ skipping 112 matching lines @@
     IPC_MESSAGE_HANDLER(UtilityHostMsg_ParseUpdateManifest_Succeeded,
                         Client::OnParseUpdateManifestSucceeded)
     IPC_MESSAGE_HANDLER(UtilityHostMsg_ParseUpdateManifest_Failed,
                         Client::OnParseUpdateManifestFailed)
     IPC_MESSAGE_HANDLER(UtilityHostMsg_DecodeImage_Succeeded,
                         Client::OnDecodeImageSucceeded)
     IPC_MESSAGE_HANDLER(UtilityHostMsg_DecodeImage_Failed,
                         Client::OnDecodeImageFailed)
   IPC_END_MESSAGE_MAP_EX()
 }