Hack to make tests work if out is a symlink: see if the current dir is the source root.

chrome/test/tab_switching/tab_switching_test.cc

 // Copyright (c) 2006-2008 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 "base/command_line.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/platform_thread.h"
 #include "chrome/app/chrome_dll_resource.h"
 #include "chrome/common/chrome_paths.h"
@@ skipping 11 matching lines @@
 
 // This Automated UI test opens static files in different tabs in a proxy
 // browser. After all the tabs have opened, it switches between tabs, and notes
 // time taken for each switch. It then prints out the times on the console,
 // with the aim that the page cycler parser can interpret these numbers to
 // draw graphs for page cycler Tab Switching Performance.
 // Usage Flags: -enable-logging -dump-histograms-on-exit
 class TabSwitchingUITest : public UITest {
  public:
   TabSwitchingUITest() {
-    PathService::Get(base::DIR_EXE, &path_prefix_);
-    path_prefix_ = path_prefix_.DirName();
-    path_prefix_ = path_prefix_.DirName();
+    PathService::Get(base::DIR_SOURCE_ROOT, &path_prefix_);
     path_prefix_ = path_prefix_.AppendASCII("data");
     path_prefix_ = path_prefix_.AppendASCII("tab_switching");
 
     show_window_ = true;
   }
 
   void RunTabSwitchingUITest() {
     // Create a browser proxy.
     browser_proxy_ = automation()->GetBrowserWindow(0);
 
@@ skipping 94 matching lines @@
 
  private:
   DISALLOW_EVIL_CONSTRUCTORS(TabSwitchingUITest);
 };
 
 TEST_F(TabSwitchingUITest, GenerateTabSwitchStats) {
   RunTabSwitchingUITest();
 }
 
 }  // namespace