Telemetry: extends Platform abstraction.

tools/telemetry/telemetry/page/page_runner.py

Index: tools/telemetry/telemetry/page/page_runner.py
diff --git a/tools/telemetry/telemetry/page/page_runner.py b/tools/telemetry/telemetry/page/page_runner.py
index 5141fdb90682f435efa212b401dc711fd72e87f0..466bb26a58794933d0c36b2be969c05162851601 100644
--- a/tools/telemetry/telemetry/page/page_runner.py
+++ b/tools/telemetry/telemetry/page/page_runner.py
@@ -142,6 +142,8 @@ class PageRunner(object):
             if options.trace_dir:
               self._SetupTracingTab(state)
 
+            self._WaitForThermalThrottlingIfNeeded(state.browser.platform)
+
             try:
               self._RunPage(options, page, state.tab, test, results)
             except exceptions.TabCrashException:
@@ -155,6 +157,8 @@ class PageRunner(object):
               logging.warning('Tab crashed: %s%s', page.url, stdout)
               state.Close()
 
+            self._CheckThermalThrottling(state.browser.platform)
+
             if options.trace_dir:
               self._EndTracing(state, options, page)
 
@@ -314,6 +318,28 @@ class PageRunner(object):
     except Exception:
       pass
 
+  def _WaitForThermalThrottlingIfNeeded(self, platform):
+    if not platform.CanMonitorThermalThrottling():
+      return
+    thermal_throttling_retry = 0
+    while (platform.IsThermallyThrottled() and
+           thermal_throttling_retry < 3):
+      logging.warning('Thermally throttled, waiting (%d)...',
+                      thermal_throttling_retry)
+      thermal_throttling_retry += 1
+      time.sleep(thermal_throttling_retry * 2)
+
+    if platform.IsThermallyThrottled():
+      logging.error('Device is thermally throttled before running '
+                    'performance tests, results will vary.')
+
+  def _CheckThermalThrottling(self, platform):
+    if not platform.CanMonitorThermalThrottling():
+      return
+    if platform.HasBeenThermallyThrottled():
+      logging.error('Device has been thermally throttled during '
+                    'performance tests, results will vary.')
+
   @staticmethod
   def AddCommandLineOptions(parser):
     page_filter_module.PageFilter.AddCommandLineOptions(parser)