Add custom interstitial for captive portals.

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 4cf189763400b171ae395513ebc5c5802fb261d6..cc70a73938c4b090ed28d38f7a64710e20dd098e 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -11269,6 +11269,14 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="interstitial.captive_portal"
+    enum="CaptivePortalBlockingPageEvent">
+  <owner>meacer@chromium.org</owner>
+  <summary>
+    User action when the user is shown a captive portal error page.
+  </summary>
+</histogram>
+
 <histogram name="interstitial.common_name_invalid_time" units="milliseconds">
   <obsolete>
     Removed on 8/1/13.
@@ -11470,6 +11478,11 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="interstitial.ssl_error_handler" enum="SSLErrorHandlerEvent">
+  <owner>meacer@chromium.org</owner>
+  <summary>The type of action that the SSL error handler takes.</summary>
+</histogram>
+
 <histogram name="interstitial.ssl_error_type" enum="SSLErrorTypes">
   <owner>felt@chromium.org</owner>
   <summary>
@@ -42977,6 +42990,11 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="3" label="webgl"/>
 </enum>
 
+<enum name="CaptivePortalBlockingPageEvent" type="int">
+  <int value="0" label="SHOW_ALL"/>
+  <int value="1" label="OPEN_LOGIN_PAGE"/>
+</enum>
+
 <enum name="CaptivePortalDetectResult" type="int">
   <int value="0" label="INTERNET_CONNECTED"/>
   <int value="1" label="NO_RESPONSE"/>
@@ -56850,6 +56868,14 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="52245" label="TLS_DHE_RSA_WITH_CHACHA20_POLY1305"/>
 </enum>
 
+<enum name="SSLErrorHandlerEvent" type="int">
+  <int value="0" label="HANDLE_ALL"/>
+  <int value="1" label="SHOW_CAPTIVE_PORTAL_INTERSTITIAL_NONOVERRIDABLE"/>
+  <int value="2" label="SHOW_CAPTIVE_PORTAL_INTERSTITIAL_OVERRIDABLE"/>
+  <int value="3" label="SHOW_SSL_INTERSTITIAL_NONOVERRIDABLE"/>
+  <int value="4" label="SHOW_SSL_INTERSTITIAL_OVERRIDABLE"/>
+</enum>
+
 <enum name="SSLErrorTypes" type="int">
   <int value="0" label="CERT_COMMON_NAME_INVALID"/>
   <int value="1" label="CERT_DATE_INVALID"/>