D2MIOS: Add plumbing to query verified number and send SMS from growth server.

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 8b647fa873307b769a21dc340e6f20e555187554..15be521ad6f7d8aa9e9be4229274dad7672262a1 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -10110,6 +10110,24 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="DesktopIOSPromotion.OAuthTokenCompletion"
+    enum="BooleanSuccess">
+  <owner>justincohen@chromium.org</owner>
+  <summary>
+    Whether getting the OAuth token was successful for a desktop to ios
+    promotion query.
+  </summary>
+</histogram>
+
+<histogram name="DesktopIOSPromotion.OAuthTokenResponseCode"
+    enum="CombinedHttpResponseAndNetErrorCode">
+  <owner>justincohen@chromium.org</owner>
+  <summary>
+    HTTP Response code returned by the server when trying to fetch the OAuth
+    token for a desktop ios promotion query.
+  </summary>
+</histogram>
+
 <histogram name="DesktopIOSPromotion.SMSToSigninTime" units="hours">
   <owner>mrefaat@chromium.org</owner>
   <summary>