chromeos: Add pref for automated brightness increases.

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index fec923fa3ed6a29985f515fda6e60323d7181e3a..b11a1487f66647c012fcfc966914c2695a778174 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -738,6 +738,11 @@ const char kPowerUserActivityScreenDimDelayFactor[] =
 const char kPowerWaitForInitialUserActivity[] =
     "power.wait_for_initial_user_activity";
 
+// Boolean controlling whether the panel backlight should be forced to a
+// nonzero level when user activity is observed.
+const char kPowerForceNonzeroBrightnessForUserActivity[] =
+    "power.force_nonzero_brightness_for_user_activity";
+
 // The URL from which the Terms of Service can be downloaded. The value is only
 // honored for public accounts.
 const char kTermsOfServiceURL[] = "terms_of_service.url";