Get rid of AX_LINE_BREAKS attribute to improve performance.

chrome/browser/extensions/api/automation/automation_apitest.cc

 // Copyright 2014 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/files/file_path.h"
 #include "base/location.h"
 #include "base/path_service.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 120 matching lines @@
       << message_;
 }
 
 IN_PROC_BROWSER_TEST_F(AutomationApiTest, BoundsForRange) {
   StartEmbeddedTestServer();
   ASSERT_TRUE(RunExtensionSubtest("automation/tests/tabs",
                                   "bounds_for_range.html"))
       << message_;
 }
 
+IN_PROC_BROWSER_TEST_F(AutomationApiTest, LineStartOffsets) {
+  StartEmbeddedTestServer();
+  ASSERT_TRUE(
+      RunExtensionSubtest("automation/tests/tabs", "line_start_offsets.html"))
+      << message_;
+}
+
 IN_PROC_BROWSER_TEST_F(AutomationApiTest, TabsAutomationBooleanPermissions) {
   StartEmbeddedTestServer();
   ASSERT_TRUE(RunExtensionSubtest(
           "automation/tests/tabs_automation_boolean", "permissions.html"))
       << message_;
 }
 
 IN_PROC_BROWSER_TEST_F(AutomationApiTest, TabsAutomationBooleanActions) {
   StartEmbeddedTestServer();
   ASSERT_TRUE(RunExtensionSubtest(
@@ skipping 110 matching lines @@
 }
 
 IN_PROC_BROWSER_TEST_F(AutomationApiTest, DocumentSelection) {
   StartEmbeddedTestServer();
   ASSERT_TRUE(
       RunExtensionSubtest("automation/tests/tabs", "document_selection.html"))
       << message_;
 }
 
 }  // namespace extensions