Chromoting browser-tests should be able to read files specified with relative paths.

chrome/test/remoting/remote_desktop_browsertest.cc

 // Copyright 2013 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/test/remoting/remote_desktop_browsertest.h"
 
 #include "base/command_line.h"
 #include "base/files/file_util.h"
 #include "base/json/json_reader.h"
 #include "base/path_service.h"
@@ skipping 803 matching lines @@
 }
 
 void RemoteDesktopBrowserTest::DismissHostVersionWarningIfVisible() {
   if (HtmlElementVisible("host-needs-update-connect-button"))
     ClickOnControl("host-needs-update-connect-button");
 }
 
 void RemoteDesktopBrowserTest::SetUserNameAndPassword(
     const base::FilePath &accounts_file_path, const std::string& account_type) {
 
-  // Read contents of accounts file.
-  std::string accounts_info;
-  ASSERT_TRUE(base::ReadFileToString(accounts_file_path, &accounts_info));
+  // ReadFileToString returns an error if the file-path is relative.
+  // Tests that run on the swarming slaves use relative paths, so we have to use
+  // ReadFile instead.
+  int64 accounts_file_size;
+  base::GetFileSize(accounts_file_path, &accounts_file_size);
+  // There is a compile error on Windows if you use a non-constant array size.
+  // For the test-accounts file, we'll assume a maximum file size of 10K.
+  char buf[10240];
+  ASSERT_FALSE(base::ReadFile(accounts_file_path, buf, accounts_file_size - 1)
+    == -1);
 
   // Get the root dictionary from the input json file contents.
+  std::string accounts_info(buf);
   scoped_ptr<base::Value> root(
       base::JSONReader::Read(accounts_info, base::JSON_ALLOW_TRAILING_COMMAS));
 
   const base::DictionaryValue* root_dict = NULL;
   ASSERT_TRUE(root.get() && root->GetAsDictionary(&root_dict));
 
   // Now get the dictionary for the specified account type.
   const base::DictionaryValue* account_dict = NULL;
   ASSERT_TRUE(root_dict->GetDictionary(account_type, &account_dict));
   ASSERT_TRUE(account_dict->GetString(kUserName, &username_));
@@ skipping 19 matching lines @@
 // static
 bool RemoteDesktopBrowserTest::IsEnabled(
     content::WebContents* client_web_content,
     const std::string& element_name) {
   return !ExecuteScriptAndExtractBool(
     client_web_content,
     "document.getElementById(\"" + element_name + "\").disabled");
 }
 
 }  // namespace remoting