PerformanceMonitor: UMA alert for high browser CPU usage.

chrome/chrome_browser.gypi

Index: chrome/chrome_browser.gypi
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index dadb388e35bdced963f897b16d06b515cc4f6da7..f1d1e8724f628a494af2f60f6bd1ac82a1f3781f 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -1355,6 +1355,8 @@
         'browser/performance_monitor/performance_monitor.h',
         'browser/performance_monitor/performance_monitor_util.cc',
         'browser/performance_monitor/performance_monitor_util.h',
+        'browser/performance_monitor/process_metrics_history.cc',
+        'browser/performance_monitor/process_metrics_history.h',
         'browser/performance_monitor/startup_timer.cc',
         'browser/performance_monitor/startup_timer.h',
         'browser/platform_util.h',
@@ -2507,14 +2509,6 @@
         'browser/webdata/web_intents_table.cc',
         'browser/webdata/web_intents_table.h',
 
-        # These files are needed by performance_monitor.cc and this dependency
-        # should be removed (crbug.com/279660)
-        'test/base/test_switches.cc',
-        'test/base/test_switches.h',
-        'test/base/chrome_process_util.cc',
-        'test/base/chrome_process_util.h',
-        'test/base/chrome_process_util_mac.cc',
-
         # These files are generated by GRIT.
         '<(grit_out_dir)/grit/component_extension_resources_map.cc',
         '<(grit_out_dir)/grit/devtools_discovery_page_resources_map.cc',