[Android] Remove some dead code in CompositorViewHolder (second try)

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

Index: chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java b/chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java
index 49d94a65db23ae1f957b81169c0e7a1cd290ba69..a5a08e38a5f3a91c9be7c5906a611df50550566c 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/compositor/CompositorViewHolder.java
@@ -112,7 +112,7 @@ public class CompositorViewHolder extends CoordinatorLayout
     private Tab mTabVisible;
 
     /** The currently attached View. */
-    private View mView;
+    private TabContentViewParent mView;
 
     private TabObserver mTabObserver;
     private boolean mEnableCompositorTabStrip;
@@ -789,10 +789,10 @@ public class CompositorViewHolder extends CoordinatorLayout
         }
         if (show) {
             if (mView.getParent() != this) {
-                // Make sure the view isn't a child of something else before we attempt to add it.
-                if (mView.getParent() instanceof ViewGroup) {
-                    ((ViewGroup) mView.getParent()).removeView(mView);
-                }
+                // During tab creation, we temporarily add the new tab's view to a FrameLayout to
+                // measure and lay it out. This way we could show the animation in the stack view.
+                // Therefore we should remove the view from that temporary FrameLayout here.
+                UiUtils.removeViewFromParent(mView);
 
                 for (int i = 0; i < sCachedCVCList.size(); i++) {
                     ContentViewCore content = sCachedCVCList.get(i);
@@ -803,19 +803,14 @@ public class CompositorViewHolder extends CoordinatorLayout
                     }
                 }
 
-                CoordinatorLayout.LayoutParams layoutParams = new CoordinatorLayout.LayoutParams(
-                        LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
-                if (mView.getLayoutParams() instanceof MarginLayoutParams) {
-                    MarginLayoutParams existingLayoutParams =
-                            (MarginLayoutParams) mView.getLayoutParams();
-                    layoutParams.leftMargin = existingLayoutParams.leftMargin;
-                    layoutParams.rightMargin = existingLayoutParams.rightMargin;
-                    layoutParams.topMargin = existingLayoutParams.topMargin;
-                    layoutParams.bottomMargin = existingLayoutParams.bottomMargin;
-                }
-                if (mView instanceof TabContentViewParent) {
-                    layoutParams.setBehavior(((TabContentViewParent) mView).getBehavior());
+                CoordinatorLayout.LayoutParams layoutParams;
+                if (mView.getLayoutParams() instanceof CoordinatorLayout.LayoutParams) {
+                    layoutParams = (CoordinatorLayout.LayoutParams) mView.getLayoutParams();
+                } else {
+                    layoutParams = new CoordinatorLayout.LayoutParams(
+                            LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
                 }
+                layoutParams.setBehavior(mView.getBehavior());
                 // CompositorView has index of 0; TabContentViewParent has index of 1; Snackbar (if
                 // any) has index of 2. Setting index here explicitly to avoid TabContentViewParent
                 // hiding the snackbar.
@@ -863,7 +858,7 @@ public class CompositorViewHolder extends CoordinatorLayout
     private void setTab(Tab tab) {
         if (tab != null) tab.loadIfNeeded();
 
-        View newView = tab != null ? tab.getView() : null;
+        TabContentViewParent newView = tab != null ? tab.getView() : null;
         if (mView == newView) return;
 
         // TODO(dtrainor): Look into changing this only if the views differ, but still parse the