Revert of [Android] Remove some dead code in CompositorViewHolder

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 4964cd706a6617ace637c5c6e78eb0c548e77186..49d94a65db23ae1f957b81169c0e7a1cd290ba69 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 @@
     private Tab mTabVisible;
 
     /** The currently attached View. */
-    private TabContentViewParent mView;
+    private View mView;
 
     private TabObserver mTabObserver;
     private boolean mEnableCompositorTabStrip;
@@ -803,14 +803,19 @@
                     }
                 }
 
-                CoordinatorLayout.LayoutParams layoutParams;
-                if (mView.getLayoutParams() != null) {
-                    layoutParams = (CoordinatorLayout.LayoutParams) mView.getLayoutParams();
-                } else {
-                    layoutParams = new CoordinatorLayout.LayoutParams(
-                            LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
+                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;
                 }
-                layoutParams.setBehavior(mView.getBehavior());
+                if (mView instanceof TabContentViewParent) {
+                    layoutParams.setBehavior(((TabContentViewParent) 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.
@@ -858,7 +863,7 @@
     private void setTab(Tab tab) {
         if (tab != null) tab.loadIfNeeded();
 
-        TabContentViewParent newView = tab != null ? tab.getView() : null;
+        View 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