Add Ctrl+Alt+H as global shortcut to toggle high contrast mode.

tools/metrics/actions/actions.xml

Index: tools/metrics/actions/actions.xml
diff --git a/tools/metrics/actions/actions.xml b/tools/metrics/actions/actions.xml
index aee7fbc4374894ab32c1990d6a371fff706ce482..9ec4041ea1ed5b292970405122e539ead3354f84 100644
--- a/tools/metrics/actions/actions.xml
+++ b/tools/metrics/actions/actions.xml
@@ -889,6 +889,14 @@ should be able to be added at any place in this file.
   <description>Please enter the description of this user action.</description>
 </action>
 
+<action name="Accel_Toggle_High_Contrast">
+  <owner>dmazzoni@chromium.org</owner>
+  <description>
+    Metric recorded when the user toggles Chrome OS High Contrast mode with the
+    keyboard accelerator (Ctrl+Alt+H).
+  </description>
+</action>
+
 <action name="Accel_Toggle_Maximized">
   <owner>Please list the metric's owners. Add more owner tags as needed.</owner>
   <description>Please enter the description of this user action.</description>
@@ -915,8 +923,8 @@ should be able to be added at any place in this file.
 </action>
 
 <action name="Accel_Toggle_Spoken_Feedback">
-  <owner>Please list the metric's owners. Add more owner tags as needed.</owner>
-  <description>Please enter the description of this user action.</description>
+  <owner>dmazzoni@chromium.org</owner>
+  <description>Toggles Spoken Feedback (ChromeVox)</description>
 </action>
 
 <action name="Accel_Toggle_Touchpad">