Revert "Update top offset of motion events on hover in CompositorViewHolder"

This reverts commit 0ef4af14.

Reason for revert: break Telemetry tests
BUG:834833

Original change's description:
> Update top offset of motion events on hover in CompositorViewHolder
> 
> When entering VR we hide the browser controls. However, it can take some
> time for this state update to reach the FullscreenManager. As a
> consequence, hover move events may have a false offset depending on
> whether the initial hover enter event was processed with the updated
> browser controls state or not. To fix that, also update the top offset
> for hover move events.
> 
> Bug: 822384
> Change-Id: I196a38098f736d6a9c8066b0a48cafa774ea1864
> Reviewed-on: https://chromium-review.googlesource.com/1014708
> Reviewed-by: Jinsuk Kim <jinsukkim@chromium.org>
> Reviewed-by: Matthew Jones <mdjones@chromium.org>
> Commit-Queue: Tibor Goldschwendt <tiborg@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#551502}

TBR=mdjones@chromium.org,jinsukkim@chromium.org,tiborg@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 822384
Change-Id: Ibb0dd8b2fe110e9f7ecd7785604f956fede4bfd3
Reviewed-on: https://chromium-review.googlesource.com/1020240Reviewed-by: Ned Nguyen <nednguyen@google.com>
Commit-Queue: Ned Nguyen <nednguyen@google.com>
Cr-Commit-Position: refs/heads/master@{#552183}

chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java

@@ -568,14 +568,7 @@ public class CompositorViewHolder extends FrameLayout
     }
 
     private void onViewportChanged() {
-        if (mLayoutManager == null) return;
-        mLayoutManager.onViewportChanged();
-        if (mTabVisible == null) return;
-        WebContents webContents = mTabVisible.getWebContents();
-        if (webContents == null) return;
-        mLayoutManager.getViewportPixel(mCacheViewport);
-        webContents.getEventForwarder().setCurrentTouchEventOffsets(
-                -mCacheViewport.left, -mCacheViewport.top);
+        if (mLayoutManager != null) mLayoutManager.onViewportChanged();
     }
 
     /**