Remove USE_LINUX_BREAKPAD ifdef since we don't need it for chromium anymore.

chrome/chrome_tests.gypi

 # 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.
 {
   'variables' : {
     'pyautolib_sources': [
       'app/chrome_command_ids.h',
       'app/chrome_dll_resource.h',
       'common/automation_constants.h',
       'common/pref_names.cc',
@@ skipping 2215 matching lines @@
                 '../base/allocator/allocator.gyp:allocator',
               ],
             }],
           ],
         }],
       ],  # conditions
     },  # target performance_browser_tests
     {
       # To run the tests from page_load_test.cc on Linux, we need to:
       #
-      #   a) Build with Breakpad (GYP_DEFINES="linux_chromium_breakpad=1")
-      #   b) Run with CHROME_HEADLESS=1 to generate crash dumps.
-      #   c) Strip the binary if it's a debug build. (binary may be over 2GB)
+      #   a) Run with CHROME_HEADLESS=1 to generate crash dumps.
+      #   b) Strip the binary if it's a debug build. (binary may be over 2GB)
       'target_name': 'reliability_tests',
       'type': 'executable',
       'dependencies': [
         'browser',
         'chrome',
         'chrome_resources.gyp:theme_resources',
         'test_support_common',
         'test_support_ui',
         'test_support_ui_runner',
         '../skia/skia.gyp:skia',
@@ skipping 1134 matching lines @@
             'utility',
           ],
           'sources': [
             'tools/service_discovery_sniffer/service_discovery_sniffer.h',
             'tools/service_discovery_sniffer/service_discovery_sniffer.cc',
           ],
         }]
     }],
   ],  # 'conditions'
 }