The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6ea15211ce9bda01f3ef0a014d30997b5fe06769

commit 6ea15211ce9bda01f3ef0a014d30997b5fe06769
Author: rlanday <rlanday@chromium.org>
Date: Tue Dec 13 03:52:22 2016

Refactor ZoomControlsDelegate out of ContentViewCore

We can keep this logic entirely in AwContents, it doesn't need to be in
ContentViewCore. I'm using the existing GestureStateListener interface to signal
AwZoomControls of the relevant events, but I did have to add a few more events
to that interface. Hopefully they're OK and will work with our future plans to
refactor more input-handling stuff out of ContentViewCore.

Note on testing this: the Android WebView shell works for testing but I had to
knock out the "&& mAwContents.getSettings().shouldDisplayZoomControls()" check
in getZoomController() to enable the zoom controls. Once you do this they appear
when scrolling.

BUG= 664339 

Review-Url: https://codereview.chromium.org/2561463004
Cr-Commit-Position: refs/heads/master@{#438045}

[modify] https://crrev.com/6ea15211ce9bda01f3ef0a014d30997b5fe06769/android_webview/java/src/org/chromium/android_webview/AwContents.java
[modify] https://crrev.com/6ea15211ce9bda01f3ef0a014d30997b5fe06769/android_webview/java/src/org/chromium/android_webview/AwZoomControls.java
[modify] https://crrev.com/6ea15211ce9bda01f3ef0a014d30997b5fe06769/content/public/android/java/src/org/chromium/content/browser/ContentView.java
[modify] https://crrev.com/6ea15211ce9bda01f3ef0a014d30997b5fe06769/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
[modify] https://crrev.com/6ea15211ce9bda01f3ef0a014d30997b5fe06769/content/public/android/java/src/org/chromium/content_public/browser/GestureStateListener.java