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 a0f850acf2461628b984f02dbda805ad851ae48e..3ac2392f1fc8c93500434ad7b4ae5f47b1914db0 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -11188,6 +11188,14 @@ 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.
@@ -11389,6 +11397,11 @@ 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>
@@ -42242,6 +42255,11 @@ 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"/>
@@ -55946,6 +55964,14 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="49323" label="TLS_PSK_DHE_WITH_AES_256_CCM_8"/>
 </enum>
 
+<enum name="SSLErrorHandlerEvent" type="int">
+  <int value="0" label="HANDLE_ALL"/>
+  <int value="1" label="SHOW_CAPTIVE_PORTAL_INTERSTITIAL"/>
+  <int value="2" label="SHOW_CAPTIVE_PORTAL_INTERSTITIAL_OVERRIDABLE"/>
+  <int value="3" label="SHOW_SSL_INTERSTITIAL"/>
+  <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"/>