[Feed] Add bottom padding on Feed NTP when Duet is enabled

Bug: 887614
Change-Id: I58bd8cf6ff9f6a59d52db2ef09fab9e0f0b48a66
Reviewed-on: https://chromium-review.googlesource.com/1239443
Commit-Queue: Becky Zhou <huayinz@chromium.org>
Reviewed-by: Theresa <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#593392}

chrome/android/feed/core/java/src/org/chromium/chrome/browser/feed/FeedNewTabPage.java

@@ -243,10 +243,12 @@ public class FeedNewTabPage extends NewTabPage {
     @Override
     protected void initializeMainView(Context context) {
         int topPadding = context.getResources().getDimensionPixelOffset(R.dimen.tab_strip_height);
+        int bottomPadding = mTab.getActivity().getFullscreenManager().getBottomControlsHeight();
+
         mRootView = new RootView(context);
         mRootView.setLayoutParams(new FrameLayout.LayoutParams(
                 FrameLayout.LayoutParams.MATCH_PARENT, FrameLayout.LayoutParams.MATCH_PARENT));
-        mRootView.setPadding(0, topPadding, 0, 0);
+        mRootView.setPadding(0, topPadding, 0, bottomPadding);
         mUiConfig = new UiConfig(mRootView);
     }