Use top browser controller height directly

Doing |getHeight() - getHeightMinusBrowserControls()| for the top toolbar
height does not work when the bottom toolbar is present since
|getHeightMinusBrowserControls()| takes into account the bottom toolbar.
The correct way to get the top toolbar height is through
|getTopBrowserControlsHeight()|.

Change-Id: I93ec1e43b8246c4babfa8a427bd9122c0a8fb39f
Reviewed-on: https://chromium-review.googlesource.com/1041218Reviewed-by: Matthew Jones <mdjones@chromium.org>
Commit-Queue: Pedro Amaral <amaralp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#555877}

chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/phone/stack/Stack.java

@@ -2457,7 +2457,7 @@ public class Stack {
     public void swipeUpdated(long time, float x, float y, float dx, float dy, float tx, float ty) {
         if (!mInSwipe) return;
 
-        final float toolbarSize = mLayout.getHeight() - mLayout.getHeightMinusBrowserControls();
+        final float toolbarSize = mLayout.getTopBrowserControlsHeight();
         if (ty > toolbarSize) mSwipeCanScroll = true;
         if (!mSwipeCanScroll) return;