Deprecate the OverviewModeBehavior and OverviewModeObserver interface

This CL annotates the OverviewModeBehavior and OverviewModeObserver
interface, and the EmptyOverviewModeObserver class as deprecated to
avoid new usage.

Change-Id: Ic1f0da301e67a0f302492c9e1f41fab3b2a5fbb3
Bug: 1108496
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2501071
Commit-Queue: Mei Liang <meiliang@chromium.org>
Reviewed-by: Matthew Jones <mdjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821358}

chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/EmptyOverviewModeObserver.java

@@ -7,8 +7,11 @@ package org.chromium.chrome.browser.compositor.layouts;
 import org.chromium.chrome.browser.compositor.layouts.OverviewModeBehavior.OverviewModeObserver;
 
 /**
-* An empty implementation of {@link OverviewModeObserver}.
-*/
+ * An empty implementation of {@link OverviewModeObserver}.
+ * DEPRECATED, please use {@link
+ * org.chromium.chrome.browser.layouts.LayoutStateProvider.LayoutStateObserver} instead.
+ */
+@Deprecated
 public class EmptyOverviewModeObserver implements OverviewModeObserver {
     @Override
     public void onOverviewModeStartedShowing(boolean showToolbar) {}

chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/OverviewModeBehavior.java

@@ -7,11 +7,18 @@ package org.chromium.chrome.browser.compositor.layouts;
 /**
  * Exposes the current overview mode state as well as a way to listen to overview mode state
  * changes.
+ *
+ * DEPRECATED, please use {@link org.chromium.chrome.browser.layouts.LayoutStateProvider} instead.
  */
+@Deprecated
 public interface OverviewModeBehavior {
     /**
      * An observer that is notified when the overview mode state changes.
+     *
+     * DEPRECATED, please use {@link
+     * org.chromium.chrome.browser.layouts.LayoutStateProvider.LayoutStateObserver} instead.
      */
+    @Deprecated
     interface OverviewModeObserver {
         /**
          * Called when overview mode starts showing.