Plumb smooth scrolling in Chromium compositor

content/public/android/java/src/org/chromium/content/browser/webcontents/WebContentsImpl.java

Index: content/public/android/java/src/org/chromium/content/browser/webcontents/WebContentsImpl.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/webcontents/WebContentsImpl.java b/content/public/android/java/src/org/chromium/content/browser/webcontents/WebContentsImpl.java
index 0f23bcda766c332bec3cbf16673ac8da8b5e75e6..5694679a60271ee25edc45ca48c1515dae7a8e2e 100644
--- a/content/public/android/java/src/org/chromium/content/browser/webcontents/WebContentsImpl.java
+++ b/content/public/android/java/src/org/chromium/content/browser/webcontents/WebContentsImpl.java
@@ -262,6 +262,11 @@ import java.util.UUID;
     }
 
     @Override
+    public void smoothScroll(int targetX, int targetY, long durationMs) {
+        nativeSmoothScroll(mNativeWebContentsAndroid, targetX, targetY, durationMs);
+    }
+
+    @Override
     public void selectWordAroundCaret() {
         nativeSelectWordAroundCaret(mNativeWebContentsAndroid);
     }
@@ -417,6 +422,8 @@ import java.util.UUID;
             boolean enableHiding, boolean enableShowing, boolean animate);
     private native void nativeShowImeIfNeeded(long nativeWebContentsAndroid);
     private native void nativeScrollFocusedEditableNodeIntoView(long nativeWebContentsAndroid);
+    private native void nativeSmoothScroll(
+            long nativeWebContentsAndroid, int targetX, int targetY, long durationMs);
     private native void nativeSelectWordAroundCaret(long nativeWebContentsAndroid);
     private native void nativeAdjustSelectionByCharacterOffset(
             long nativeWebContentsAndroid, int startAdjust, int endAdjust);