Remove most native WebContents references from Java

content/shell/android/java/src/org/chromium/content_shell/Shell.java

Index: content/shell/android/java/src/org/chromium/content_shell/Shell.java
diff --git a/content/shell/android/java/src/org/chromium/content_shell/Shell.java b/content/shell/android/java/src/org/chromium/content_shell/Shell.java
index 79edb4858f2b464daa694c971b9145248c946340..4a40a5184509f2350f111dd8d507c666b31f166d 100644
--- a/content/shell/android/java/src/org/chromium/content_shell/Shell.java
+++ b/content/shell/android/java/src/org/chromium/content_shell/Shell.java
@@ -286,15 +286,15 @@ public class Shell extends LinearLayout {
 
     /**
      * Initializes the ContentView based on the native tab contents pointer passed in.
-     * @param nativeWebContents The pointer to the native tab contents object.
+     * @param webContents A {@link WebContents} object.
      */
     @SuppressWarnings("unused")
     @CalledByNative
-    private void initFromNativeTabContents(long nativeWebContents) {
+    private void initFromNativeTabContents(WebContents webContents) {
         Context context = getContext();
         mContentViewCore = new ContentViewCore(context);
         ContentView cv = ContentView.newInstance(context, mContentViewCore);
-        mContentViewCore.initialize(cv, cv, nativeWebContents, mWindow);
+        mContentViewCore.initialize(cv, cv, webContents, mWindow);
         mContentViewCore.setContentViewClient(mContentViewClient);
         mWebContents = mContentViewCore.getWebContents();
         mNavigationController = mWebContents.getNavigationController();