WebViewChromiumFactoryProvider should import ResourceExtractor fromorg.chromium.base

Chromium repository CL, https://codereview.chromium.org/548023002 will migrate
ResourceExtractor.java inside org.chromium.base package.

The same should be reflected while importing ResourceExtractor in
WebViewChromiumFactoryProvider.java

Change-Id: Iced2182763d6e0769003c3bb096465ca8bbf68ac
Merge "WebViewChromiumFactoryProvider should import ResourceExtractor fromorg.chromium.base" into chromium-dev