Delete code involving overdraw bottom height.

chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorView.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;
 
 import android.app.Activity;
 import android.content.Context;
 import android.graphics.Color;
 import android.graphics.PixelFormat;
@@ skipping 129 matching lines @@
                 heightMeasureSpec =
                         MeasureSpec.makeMeasureSpec(getMeasuredHeight(), MeasureSpec.EXACTLY);
             }
         }
         super.onMeasure(widthMeasureSpec, heightMeasureSpec);
     }
 
     @Override
     protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
         super.onLayout(changed, left, top, right, bottom);
-        mRenderHost.onOverdrawBottomHeightChanged(getOverdrawBottomHeight());
     }
 
     @Override
     protected void onDetachedFromWindow() {
         super.onDetachedFromWindow();
         mPreviousWindowTop = -1;
     }
 
     /**
      * @return The ResourceManager.
      */
     public ResourceManager getResourceManager() {
         return mResourceManager;
     }
 
     /**
-     * @return The amount the surface view is overdrawing the window bounds.
-     */
-    public int getOverdrawBottomHeight() {
-        if (mRootActivityView == null) {
-            mRootActivityView = mRootView.findViewById(android.R.id.content);
-        }
-        if (mRootActivityView != null) {
-            int compositorHeight = getHeight();
-            int rootViewHeight = mRootActivityView.getHeight();
-            return Math.max(0, compositorHeight - rootViewHeight);
-        }
-        return 0;
-    }
-
-    /**
      * Should be called for cleanup when the CompositorView instance is no longer used.
      */
     public void shutDown() {
         getHolder().removeCallback(this);
         if (mNativeCompositorView != 0) nativeDestroy(mNativeCompositorView);
         mNativeCompositorView = 0;
     }
 
     /**
      * Initializes the {@link CompositorView}'s native parts (e.g. the rendering parts).
@@ skipping 213 matching lines @@
 
         // IMPORTANT: Do not do anything that impacts the compositor layer tree before this line.
         // If you do, you could inadvertently trigger follow up renders.  For further information
         // see dtrainor@, tedchoc@, or klobag@.
 
         // TODO(jscholler): change 1.0f to dpToPx once the native part is fully supporting dp.
         mRenderHost.getVisibleViewport(mCacheVisibleViewport);
         provider.getViewportPixel(mCacheViewport);
         nativeSetLayoutViewport(mNativeCompositorView, mCacheViewport.left, mCacheViewport.top,
                 mCacheViewport.width(), mCacheViewport.height(), mCacheVisibleViewport.left,
-                mCacheVisibleViewport.top, mRenderHost.getCurrentOverdrawBottomHeight(), 1.0f);
-
-        mCacheVisibleViewport.right = mCacheVisibleViewport.left + mSurfaceWidth;
-        mCacheVisibleViewport.bottom = mCacheVisibleViewport.top
-                + Math.max(mSurfaceHeight - mRenderHost.getCurrentOverdrawBottomHeight(), 0);
+                mCacheVisibleViewport.top, 1.0f);
 
         // TODO(changwan): move to treeprovider.
         updateToolbarLayer(provider, forRotation, progressBarDrawingInfo);
 
         SceneLayer sceneLayer =
                 provider.getUpdatedActiveSceneLayer(mCacheViewport, mCacheVisibleViewport,
                         mLayerTitleCache, mTabContentManager, mResourceManager,
                         provider.getFullscreenManager());
 
         nativeSetSceneLayer(mNativeCompositorView, sceneLayer);
@@ skipping 27 matching lines @@
     private native void nativeDestroy(long nativeCompositorView);
     private native ResourceManager nativeGetResourceManager(long nativeCompositorView);
     private native void nativeSurfaceCreated(long nativeCompositorView);
     private native void nativeSurfaceDestroyed(long nativeCompositorView);
     private native void nativeSurfaceChanged(
             long nativeCompositorView, int format, int width, int height, Surface surface);
     private native void nativeFinalizeLayers(long nativeCompositorView);
     private native void nativeSetNeedsComposite(long nativeCompositorView);
     private native void nativeSetLayoutViewport(long nativeCompositorView, float x, float y,
             float width, float height, float visibleXOffset, float visibleYOffset,
-            float overdrawBottomHeight, float dpToPixel);
+            float dpToPixel);
     private native void nativeUpdateToolbarLayer(long nativeCompositorView, int resourceId,
             int toolbarBackgroundColor, int urlBarResourceId, float urlBarAlpha, float topOffset,
             float brightness, boolean visible, boolean showShadow);
     private native void nativeUpdateProgressBar(
             long nativeCompositorView,
             int progressBarX,
             int progressBarY,
             int progressBarWidth,
             int progressBarHeight,
             int progressBarColor,
             int progressBarBackgroundX,
             int progressBarBackgroundY,
             int progressBarBackgroundWidth,
             int progressBarBackgroundHeight,
             int progressBarBackgroundColor);
     private native void nativeSetOverlayVideoMode(long nativeCompositorView, boolean enabled);
     private native void nativeSetSceneLayer(long nativeCompositorView, SceneLayer sceneLayer);
 }