Add performance_tests_browser to the GN build.

BUILD.gn

 # Copyright (c) 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.
 
 # This is the root build file for GN. GN will start processing by loading this
 # file, and recursively load all dependencies until all dependencies are either
 # resolved or known not to exist (which will cause the build to fail). So if
 # you add a new build file, there must be some path of dependencies from this
 # file to your new one or GN won't know about it.
 
@@ skipping 234 matching lines @@
       "//base:check_example",
       "//base:protect_file_posix",
       "//base:build_utf8_validator_tables",
       "//breakpad:core-2-minidump",
       "//breakpad:minidump-2-core",
       "//build/sanitizers:copy_llvm_symbolizer",
       "//cc/blink:cc_blink_unittests",
       "//cc:cc_perftests",
       "//chrome/test:chrome_app_unittests",
       "//chrome/test:load_library_perf_tests",
+      "//chrome/test:performance_browser_tests",
       "//chrome/test:sync_performance_tests",
       "//chrome/test/chromedriver:chromedriver",
       "//chrome/test/chromedriver:chromedriver_tests",
       "//chrome/tools/profile_reset:jtl_compiler",
       "//components:components_perftests",
       "//components/network_hints/browser",
       "//components/webui_generator",
       "//content/public/app:browser",
       "//content/public/app:child",
       "//content/test:content_gl_tests",
@@ skipping 392 matching lines @@
 
       # Note:
       # (*) Fails but failures match GYP build at time of testing.
     ]
 
     if (enable_nacl) {
       deps += [ "//components/nacl:nacl_loader_unittests" ]  # PASSES 3/28/2015
     }
   }
 }