Make browser_tests obey BROWSER_WRAPPER, like how ui_tests do.

chrome/test/out_of_proc_test_runner.cc

 // Copyright (c) 2010 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 <string>
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/linked_ptr.h"
@@ skipping 257 matching lines @@
   // Create a new user data dir and pass it to the child.
   ScopedTempDir temp_dir;
   if (!temp_dir.CreateUniqueTempDir() || !temp_dir.IsValid()) {
     LOG(ERROR) << "Error creating temp profile directory";
     return false;
   }
   new_cmd_line.AppendSwitchPath(switches::kUserDataDir, temp_dir.path());
 
   base::ProcessHandle process_handle;
 #if defined(OS_POSIX)
+  const char* browser_wrapper = getenv("BROWSER_WRAPPER");
+  if (browser_wrapper) {
+    new_cmd_line.PrependWrapper(browser_wrapper);
+    VLOG(1) << "BROWSER_WRAPPER was set, prefixing command_line with "
+            << browser_wrapper;
+  }
+
   // On POSIX, we launch the test in a new process group with pgid equal to
   // its pid. Any child processes that the test may create will inherit the
   // same pgid. This way, if the test is abruptly terminated, we can clean up
   // any orphaned child processes it may have left behind.
   base::environment_vector no_env;
   base::file_handle_mapping_vector no_files;
   if (!base::LaunchAppInNewProcessGroup(new_cmd_line.argv(), no_env, no_files,
                                         false, &process_handle))
     return false;
 #else
@@ skipping 211 matching lines @@
       exit_code = 1;
       break;
     }
 
     // Special value "-1" means "repeat indefinitely".
     if (cycles != -1)
       cycles--;
   }
   return exit_code;
 }