Remove implementation map from ChromeApplication

chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java b/chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java
index a15c2f93b5271900e45964e21493373028c209c6..2a973473ef9c52ed815d48f98dbb072e92580b95 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ChromeApplication.java
@@ -11,7 +11,6 @@ import android.content.SharedPreferences;
 import android.os.Handler;
 import android.os.Looper;
 import android.os.SystemClock;
-import android.support.v4.util.ArrayMap;
 import android.util.Log;
 
 import org.chromium.base.ActivityState;
@@ -67,8 +66,6 @@ import org.chromium.content.browser.ChildProcessCreationParams;
 import org.chromium.policy.AppRestrictionsProvider;
 import org.chromium.policy.CombinedPolicyProvider;
 
-import java.util.Map;
-
 /**
  * Basic application functionality that should be shared among all browser applications that use
  * chrome layer.
@@ -84,17 +81,10 @@ public class ChromeApplication extends ContentApplication {
 
     private static DocumentTabModelSelector sDocumentTabModelSelector;
 
-    protected Map<Class, Class> mImplementationMap;
-
     @Override
     protected void attachBaseContext(Context base) {
         super.attachBaseContext(base);
         ContextUtils.initApplicationContext(this);
-
-        // This field may be used before onCreate is called, so we need to create it here.
-        // It may be wise to update this anticipated capacity from time time as expectations for
-        // the quantity of downsteam-specific implementations increases (or decreases).
-        mImplementationMap = new ArrayMap<Class, Class>(8);
     }
 
     /**
@@ -430,39 +420,4 @@ public class ChromeApplication extends ContentApplication {
     public AccountManagerDelegate createAccountManagerDelegate() {
         return new SystemAccountManagerDelegate(this);
     }
-
-    /**
-     * Instantiates an object of a given type.
-     * This method exists as a utility to generate objects of types that have different
-     * implementations upstream and downstream.  To use this,
-     * - give the upstream class a public parameterless constructor (required!)
-     *   e.g., public MyType() {},
-     * - register the downstream object in mImplementationMap,
-     *   e.g., mImplementationMap.put(MyType.class, MySubType.class);
-     * - invoke this method on the appropriate class,
-     *   e.g., ChromeApplication.createObject(MyType.class).
-     * @param klass The class that the Chrome Application should create an instance of.
-     */
-    @SuppressWarnings("unchecked")
-    public static <T> T createObject(Class<T> klass) {
-        Class newKlass = ((ChromeApplication) ContextUtils.getApplicationContext())
-                .mImplementationMap.get(klass);
-        if (newKlass == null) {
-            newKlass = klass;
-        }
-
-        Object obj;
-        try {
-            obj = newKlass.newInstance();
-        } catch (InstantiationException e) {
-            throw new RuntimeException("Asked to create unexpected class: " + klass.getName(), e);
-        } catch (IllegalAccessException e) {
-            throw new RuntimeException("Asked to create unexpected class: " + klass.getName(), e);
-        }
-        if (!klass.isInstance(obj)) {
-            throw new RuntimeException("Created an instance of type " + obj.getClass().getName()
-                    + " when expected an instance of type " + klass.getName());
-        }
-        return (T) obj;
-    }
 }