Record device screen state and system load (from /proc/loadavg).

Bug: http://b/19483574

(cherry picked from commit ebb946827ffbbb7df4c41be262a627c02bd95888)

Change-Id: I2a00e1fb075131e7d7d1a45c196ab0ac414e39c0
diff --git a/perfprofd/perf_profile.proto b/perfprofd/perf_profile.proto
index ee34163..3932a16 100644
--- a/perfprofd/perf_profile.proto
+++ b/perfprofd/perf_profile.proto
@@ -91,4 +91,12 @@
 
   // List of all load modules.
   repeated LoadModule load_modules = 4;
-}
\ No newline at end of file
+
+  // is device screen on at point when profile is collected?
+  optional bool display_on = 5;
+
+  // system load at point when profile is collected; corresponds
+  // to first value from /proc/loadavg multiplied by 100 then
+  // converted to int32
+  optional int32 sys_load_average = 6;
+}