Fix http://crbug.com/85522

WebDatabase uses an authorizer to prevent inappropriate access.
fts3.c uses 'PRAGMA page_size' to tune the query optimizer, but PRAGMA
is on the disallowed list.  This patch adds a default return value for
SQLITE_AUTH failures.

diff --git src/ext/fts3/fts3.c src/ext/fts3/fts3.c
index 8498cfa..dfa3891 100644
--- src/ext/fts3/fts3.c
+++ src/ext/fts3/fts3.c
@@ -630,6 +630,9 @@ static void fts3DatabasePageSize(int *pRc, Fts3Table *p){
         sqlite3_step(pStmt);
         p->nPgsz = sqlite3_column_int(pStmt, 0);
         rc = sqlite3_finalize(pStmt);
+      }else if( rc==SQLITE_AUTH ){
+        p->nPgsz = 1024;
+        rc = SQLITE_OK;
       }
     }
     assert( p->nPgsz>0 || rc!=SQLITE_OK );