Send UMA about requested window state from tabs API

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 55bbc66dd3f65704f415da0d687b580b6a3b6d6b..03d34fff9944b9fbcc31dd6bf541d42a70ff7e9b 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -72639,6 +72639,13 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </details>
 </histogram>
 
+<histogram name="TabsApi.RequestedWindowState" enum="RequestedWindowState">
+  <owner>afakhry@chromium.org</owner>
+  <summary>
+    The requested window creation state from the tabs extensions API.
+  </summary>
+</histogram>
+
 <histogram name="TaskScheduler.BlockShutdownTasksPostedDuringShutdown"
     units="tasks">
   <owner>fdoray@chromium.org</owner>
@@ -108287,6 +108294,15 @@ from previous Chrome versions.
   <int value="7" label="Unknown"/>
 </enum>
 
+<enum name="RequestedWindowState" type="int">
+  <int value="0" label="Invalid"/>
+  <int value="1" label="Normal window state"/>
+  <int value="2" label="Minimized window state"/>
+  <int value="3" label="Maximized window state"/>
+  <int value="4" label="Fullscreen window state"/>
+  <int value="5" label="Docked window state"/>
+</enum>
+
 <enum name="RequestMediaKeySystemAccessStatus" type="int">
   <int value="0" label="Requested"/>
   <int value="1" label="Supported"/>