Update WebView#loadDataWithBaseURL documentation. DO NOT MERGE

Trivial cherry pick from master, see
Id1182537e073a9dd7746e23eec20accacedd9fc8

historyURL must be a valid URL.

Bug: 7907196
Change-Id: I1f32a9bda4ae627f242b2533eca18aef3ba25411
1 file changed