Add an extension API to verify server certificate trust.

BUG=476464

Review URL: https://codereview.chromium.org/1066383002

Cr-Commit-Position: refs/heads/master@{#331236}
diff --git a/extensions/browser/extension_function_histogram_value.h b/extensions/browser/extension_function_histogram_value.h
index 8a7081c0..e183baf 100644
--- a/extensions/browser/extension_function_histogram_value.h
+++ b/extensions/browser/extension_function_histogram_value.h
@@ -1099,6 +1099,7 @@
   PASSWORDSPRIVATE_REMOVEPASSWORDEXCEPTION,
   PASSWORDSPRIVATE_GETPLAINTEXTPASSWORD,
   LAUNCHERPAGE_HIDE,
+  PLATFORMKEYS_VERIFYTLSSERVERCERTIFICATE,
   // Last entry: Add new entries above and ensure to update
   // tools/metrics/histograms/histograms.xml.
   ENUM_BOUNDARY