Add API for custom library loading

components/cronet/android/test/javatests/src/org/chromium/net/CronetUrlRequestContextTest.java

 // Copyright 2014 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.net;
 
 import static org.chromium.base.CollectionUtil.newHashSet;
 
 import android.content.Context;
 import android.content.ContextWrapper;
@@ skipping 942 matching lines @@
         builder.setDataReductionProxyOptions("mnop", "qrst", "uvwx");
         builder.setStoragePath(CronetTestFramework.getTestStorage(getContext()));
         nativeVerifyUrlRequestContextConfig(
                 CronetUrlRequestContext.createNativeUrlRequestContextConfig(builder),
                 CronetTestFramework.getTestStorage(getContext()));
     }
 
     // Verifies that CronetEngine.Builder config from testCronetEngineBuilderConfig() is properly
     // translated to a native UrlRequestContextConfig.
     private static native void nativeVerifyUrlRequestContextConfig(long config, String storagePath);
+
+    private static class TestBadLibraryLoader extends CronetEngine.Builder.LibraryLoader {
+        private boolean mWasCalled = false;
+
+        public void loadLibrary(String libName) {
+            // Report that this method was called, but don't load the library
+            mWasCalled = true;
+        }
+
+        boolean wasCalled() {
+            return mWasCalled;
+        }
+    }
+
+    @SmallTest
+    @Feature({"Cronet"})
+    public void testSkipLibraryLoading() throws Exception {
+        CronetEngine.Builder builder = new CronetEngine.Builder(getContext());
+        TestBadLibraryLoader loader = new TestBadLibraryLoader();
+        builder.setLibraryLoader(loader).setLibraryName("cronet_tests");
+        try {
+            // ensureInitialized() calls native code to check the version right after library load
+            // and will error with the message below if library loading was skipped
+            CronetLibraryLoader.ensureInitialized(getContext(), builder);
+            fail("Native library should not be loaded");
+        } catch (UnsatisfiedLinkError e) {
+            assertTrue(e.getMessage().contains(
+                    "No implementation found for java.lang.String org.chromium.net"));
+            assertTrue(loader.wasCalled());
+        }
+    }
 }