Push API: Don't wait for network when unsubscribing

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 db0258319ce14ea934ea95de8bf9efb534e836ed..fca08ba46403f4496adf54b157d8f76f38bc3763 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -52652,6 +52652,24 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="PushMessaging.UnregistrationGCMResult" enum="GCMClientResult">
+  <owner>johnme@google.com</owner>
+  <summary>
+    When unregistering a legacy non-InstanceID push messaging subscription, this
+    records the result returned by the GCMDriver (note that exceeding the
+    maximum number of retries due to network errors is logged as SERVER_ERROR).
+  </summary>
+</histogram>
+
+<histogram name="PushMessaging.UnregistrationIIDResult" enum="InstanceIDResult">
+  <owner>johnme@google.com</owner>
+  <summary>
+    When unregistering an InstanceID push messaging subscription, this records
+    the result returned from deleting the InstanceID (note that exceeding the
+    maximum number of retries due to network errors is logged as SERVER_ERROR).
+  </summary>
+</histogram>
+
 <histogram name="PushMessaging.UnregistrationReason"
     enum="PushUnregistrationReason">
   <owner>johnme@google.com</owner>
@@ -92489,6 +92507,17 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="6" label="Zero ID or token"/>
 </enum>
 
+<enum name="GCMClientResult" type="int">
+  <int value="0" label="Success"/>
+  <int value="1" label="Invalid parameter"/>
+  <int value="2" label="GCM disabled"/>
+  <int value="3" label="Async operation pending"/>
+  <int value="4" label="Network error"/>
+  <int value="5" label="Server error"/>
+  <int value="6" label="TTL exceeded"/>
+  <int value="7" label="Unknown error"/>
+</enum>
+
 <enum name="GCMConnectionResetReason" type="int">
   <int value="0" label="Login failure"/>
   <int value="1" label="Close command"/>
@@ -94430,6 +94459,18 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="63" label="DELETE_OLD_VERSIONS_TOO_MANY_ATTEMPTS"/>
 </enum>
 
+<enum name="InstanceIDResult" type="int">
+  <int value="0" label="Success"/>
+  <int value="1" label="Invalid parameter"/>
+  <int value="2" label="GCM disabled"/>
+  <int value="3" label="Async operation pending"/>
+  <int value="4" label="Network error"/>
+  <int value="5" label="Server error"/>
+<!-- 6 is omitted, in case we ever merge this enum with GCMClientResult. -->
+
+  <int value="7" label="Unknown error"/>
+</enum>
+
 <enum name="InstantAppsCallSource" type="int">
   <int value="1" label="Loading screen"/>
   <int value="2" label="Notification"/>