Revert "VR: Remove bottom margin from NTP"

This reverts commit 31783d1f.

Reason for revert: Crash when opening a new tab.

Original change's description:
> VR: Remove bottom margin from NTP
> 
> Bug: 884803
> Change-Id: I20378649418949c2d00097ff8ca204972c54b2ab
> Reviewed-on: https://chromium-review.googlesource.com/1240169
> Reviewed-by: Theresa <twellington@chromium.org>
> Reviewed-by: Matthew Jones <mdjones@chromium.org>
> Commit-Queue: Aldo Culquicondor <acondor@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#595884}

TBR=twellington@chromium.org,mdjones@chromium.org,acondor@chromium.org

Change-Id: Ifef474e5c9183a32934a1eeb401c2a5e7e3e505f
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 884803
Reviewed-on: https://chromium-review.googlesource.com/c/1258299Reviewed-by: Aldo Culquicondor <acondor@chromium.org>
Commit-Queue: Aldo Culquicondor <acondor@chromium.org>
Cr-Commit-Position: refs/heads/master@{#596224}

chrome/android/java/src/org/chromium/chrome/browser/fullscreen/ChromeFullscreenManager.java

@@ -357,7 +357,7 @@ public class ChromeFullscreenManager
 
     @Override
     public int getBottomControlsHeight() {
-        return VrModuleProvider.getDelegate().isInVr() ? 0 : mBottomControlContainerHeight;
+        return mBottomControlContainerHeight;
     }
 
     /**

chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java

@@ -280,7 +280,7 @@ public class NewTabPageView extends FrameLayout {
 
         if (FeatureUtilities.isBottomToolbarEnabled()) {
             ((MarginLayoutParams) getLayoutParams()).bottomMargin =
-                    mTab.getFullscreenManager().getBottomControlsHeight();
+                    getResources().getDimensionPixelSize(R.dimen.bottom_toolbar_height);
         }
     }