[Android] Fix a subtle issue in Java Bridge regarding interfaces removal

content/public/android/javatests/src/org/chromium/content/browser/JavaBridgeBasicsTest.java

 // Copyright 2012 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.content.browser;
 
 import android.test.suitebuilder.annotation.SmallTest;
 
 import org.chromium.base.test.util.Feature;
 import org.chromium.content.browser.test.util.TestCallbackHelperContainer;
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             }
         });
         assertEquals("undefined", executeJavaScriptAndGetStringResult("typeof testObject"));
         synchronousPageReload();
         assertEquals("object", executeJavaScriptAndGetStringResult("typeof testObject"));
     }
 
     @SmallTest
     @Feature({"AndroidWebView", "Android-JavaBridge"})
     public void testRemovalNotReflectedUntilReload() throws Throwable {
-        injectObjectAndReload(new Object(), "testObject");
+        injectObjectAndReload(new Object() {
+            public void method() {
+                mTestController.setStringValue("I'm here");
+            }
+        }, "testObject");
         assertEquals("object", executeJavaScriptAndGetStringResult("typeof testObject"));
+        executeJavaScript("testObject.method()");
+        assertEquals("I'm here", mTestController.waitForStringValue());
         runTestOnUiThread(new Runnable() {
             @Override
             public void run() {
                 getContentViewCore().removeJavascriptInterface("testObject");
             }
         });
+        // Check that the Java object is being held by the Java bridge, thus it's not
+        // collected. Note that despite that what JavaDoc says about invoking "gc()", both Dalvik
+        // and ART actually run the collector if called via Runtime.
+        Runtime.getRuntime().gc();
         assertEquals("object", executeJavaScriptAndGetStringResult("typeof testObject"));
+        executeJavaScript("testObject.method()");
+        assertEquals("I'm here", mTestController.waitForStringValue());
         synchronousPageReload();
         assertEquals("undefined", executeJavaScriptAndGetStringResult("typeof testObject"));
     }
 
     @SmallTest
     @Feature({"AndroidWebView", "Android-JavaBridge"})
     public void testRemoveObjectNotAdded() throws Throwable {
         TestCallbackHelperContainer.OnPageFinishedHelper onPageFinishedHelper =
                 mTestCallbackHelperContainer.getOnPageFinishedHelper();
         int currentCallCount = onPageFinishedHelper.getCallCount();
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         }
         injectObjectAndReload(new Test(13), "testObject");
         assertEquals("13", executeJavaScriptAndGetStringResult("testObject.getValue()"));
         // The documentation doesn't specify, what happens if the embedder is trying
         // to inject a different object under the same name. The current implementation
         // simply replaces the old object with the new one.
         injectObjectAndReload(new Test(42), "testObject");
         assertEquals("42", executeJavaScriptAndGetStringResult("testObject.getValue()"));
     }
 }