[doc] add public docs about Webview Policies

docs/webview_policies.md

Index: docs/webview_policies.md
diff --git a/docs/webview_policies.md b/docs/webview_policies.md
new file mode 100644
index 0000000000000000000000000000000000000000..d4d671a48f5f46ef4b79acb100f6d0c1e5e0502e
--- /dev/null
+++ b/docs/webview_policies.md
@@ -0,0 +1,22 @@
+# WebView Policies
+
+## Overview
+
+WebView supports a subset of Chrome's policies, that can be set via the
+[App Restrictions][1] mechanism. They are read on the embedder app itself rather
+than from a centralized location. That gives administrator more flexibility and
+granularity, but to apply a global policy, it has to be set separately
+on each app.
+
+The policies will be applied to WebViews used inside the targeted apps without
+having to modify the apps themselves. No special WebView APIs have been added
+to expose policy information. If developers want to change their app's behavior
+depending on that, they can [read them][2] as they have access to the
+App Restrictions.
+
+Please see the [Policy List on chromium.org][2] for more information and the
+list of supported policies.
+
+[3]: http://developer.android.com/training/enterprise/work-policy-ctrl.html#apply_restrictions
+[1]: http://developer.android.com/training/enterprise/app-restrictions.html
+[2]: https://www.chromium.org/administrators/policy-list-3