Refactor android_webview_shell and its tests

android_webview/tools/WebViewShell/src/org/chromium/webview_shell/WebViewLayoutTestRunner.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.webview_shell;
-
-import android.os.Bundle;
-import android.test.InstrumentationTestRunner;
-
-/**
- * Customized test runner for running instrumentation tests in WebViewBrowserTests.
- */
-public class WebViewLayoutTestRunner extends InstrumentationTestRunner {
-    private String mModeArgument;
-    private static final String MODE_REBASELINE = "rebaseline";
-
-    @Override
-    public void onCreate(Bundle arguments) {
-        super.onCreate(arguments);
-        if (arguments != null) {
-            mModeArgument = arguments.getString("mode");
-        }
-    }
-
-    public boolean isRebaseline() {
-        return mModeArgument != null ? mModeArgument.equals(MODE_REBASELINE) : false;
-    }
-}