[Telemetry] Power metric: subtract quiescent power draw from result

tools/telemetry/telemetry/core/platform/power_monitor/__init__.py

Index: tools/telemetry/telemetry/core/platform/power_monitor/__init__.py
diff --git a/tools/telemetry/telemetry/core/platform/power_monitor/__init__.py b/tools/telemetry/telemetry/core/platform/power_monitor/__init__.py
index 4d98e075d6057a56a331b01934d6437961f1ac22..7a13fa91d2b2de33e6024e89547bafc3ba7c6e15 100644
--- a/tools/telemetry/telemetry/core/platform/power_monitor/__init__.py
+++ b/tools/telemetry/telemetry/core/platform/power_monitor/__init__.py
@@ -16,6 +16,12 @@ class PowerMonitor(object):
     """
     return False
 
+  def CanMeasurePerApplicationPower(self):
+    """Returns True if the power monitor can measure power for the target
+    application in isolation. False if power measurement is for full system
+    energy consumption."""
+    return False
+
   def StartMonitoringPower(self, browser):
     """Starts monitoring power utilization statistics.