Refactor OverlayPanel height calculations

chrome/android/java/src/org/chromium/chrome/browser/compositor/layouts/Layout.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser.compositor.layouts;
 
 import static org.chromium.chrome.browser.compositor.layouts.ChromeAnimation.AnimatableAnimation.createAnimation;
 
 import android.content.Context;
 import android.graphics.Point;
@@ skipping 344 matching lines @@
      *
      * @param context     The current Android's context.
      */
     public void contextChanged(Context context) {
         mContext = context;
         LayoutTab.resetDimensionConstants(context);
     }
 
     /**
      * Called when the size of the viewport has changed.
-     * @param availableViewport      The actual viewport this {@link Layout} should be rendering to.
      * @param visibleViewport        The visible viewport that represents the area on the screen
      *                               this {@link Layout} gets to draw to (potentially takes into
      *                               account top controls).
      * @param screenViewport         The viewport of the screen.
      * @param heightMinusTopControls The height the {@link Layout} gets excluding the height of the
      *                               top controls.  TODO(dtrainor): Look at getting rid of this.
      * @param orientation            The new orientation.  Valid values are defined by
      *                               {@link Orientation}.
      */
-    public final void sizeChanged(RectF availableViewport, RectF visibleViewport,
-            RectF screenViewport, float heightMinusTopControls, int orientation) {
-        // 1. Pull out this Layout's specific width and height properties based on the available
-        // viewport.
-        float width = availableViewport.width();
-        float height = availableViewport.height();
+    public final void sizeChanged(RectF visibleViewport, RectF screenViewport,
+            float heightMinusTopControls, int orientation) {
+        // 1. Pull out this Layout's width and height properties based on the viewport.
+        float width = screenViewport.width();
+        float height = screenViewport.height();
 
         // 2. Check if any Layout-specific properties have changed.
         boolean layoutPropertiesChanged = mWidth != width
                 || mHeight != height
                 || mHeightMinusTopControls != heightMinusTopControls
                 || mCurrentOrientation != orientation;
 
         // 3. Update the internal sizing properties.
         mWidth = width;
         mHeight = height;
@@ skipping 824 matching lines @@
 
     /**
      * Update {@link SceneLayer} instance this layout holds. Any class inheriting {@link Layout}
      * should override this function in order for other functions to work.
      */
     protected void updateSceneLayer(Rect viewport, Rect contentViewport,
             LayerTitleCache layerTitleCache, TabContentManager tabContentManager,
             ResourceManager resourceManager, ChromeFullscreenManager fullscreenManager) {
     }
 }