service worker: Implement NavigationPreloadManager.getState

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 6c3cd2e3d148e3a752fdc0ce7062fbaf1d5e9b59..7ade8da3468a6aacc2729fa5b974a8b94695e6da 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -74238,6 +74238,12 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="143" label="SWDH_ENABLE_NAVIGATION_PRELOAD_NO_HOST"/>
   <int value="144" label="SWDH_ENABLE_NAVIGATION_PRELOAD_INVALID_ORIGIN"/>
   <int value="145" label="SWDH_ENABLE_NAVIGATION_PRELOAD_BAD_REGISTRATION_ID"/>
+  <int value="146" label="RDH_TRANSFERRING_REQUEST_NOT_FOUND"/>
+  <int value="147" label="RDH_TRANSFERRING_NONNAVIGATIONAL_REQUEST"/>
+  <int value="148" label="SWDH_GET_NAVIGATION_PRELOAD_STATE_NO_HOST"/>
+  <int value="149" label="SWDH_GET_NAVIGATION_PRELOAD_STATE_INVALID_ORIGIN"/>
+  <int value="150"
+      label="SWDH_GET_NAVIGATION_PRELOAD_STATE_BAD_REGISTRATION_ID"/>
 </enum>
 
 <enum name="BadMessageReasonExtensions" type="int">