Fix of flaky SdchTest#testSdchEnabled test.

BUG=657413
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_cronet_tester

Review-Url: https://codereview.chromium.org/2709003002
Cr-Commit-Position: refs/heads/master@{#451872}

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

@@ -4,7 +4,6 @@
 
 package org.chromium.net;
 
-import android.os.ConditionVariable;
 import android.support.test.filters.SmallTest;
 
 import org.json.JSONException;
@@ -71,7 +70,7 @@ public void testSdchEnabled() throws Exception {
         String targetUrl = NativeTestServer.getSdchURL() + "/sdch/test";
         long contextAdapter =
                 getContextAdapter((CronetUrlRequestContext) mTestFramework.mCronetEngine);
-        DictionaryAddedObserver observer = new DictionaryAddedObserver(targetUrl, contextAdapter);
+        SdchObserver observer = new SdchObserver(targetUrl, contextAdapter);
 
         // Make a request to /sdch which advertises the dictionary.
         TestUrlRequestCallback callback1 = startAndWaitForComplete(mTestFramework.mCronetEngine,
@@ -101,8 +100,7 @@ public void testSdchEnabled() throws Exception {
                 null, mTestFramework.getCronetEngineBuilder());
         CronetUrlRequestContext newContext = (CronetUrlRequestContext) mTestFramework.mCronetEngine;
         long newContextAdapter = getContextAdapter(newContext);
-        DictionaryAddedObserver newObserver =
-                new DictionaryAddedObserver(targetUrl, newContextAdapter);
+        SdchObserver newObserver = new SdchObserver(targetUrl, newContextAdapter);
         newObserver.waitForDictionaryAdded();
 
         // Make a request to fetch encoded response at /sdch/test.
@@ -146,27 +144,6 @@ public void testDictionaryNotFound() throws Exception {
         assertEquals("Sdch is not used.\n", callback2.mResponseAsString);
     }
 
-    private static class DictionaryAddedObserver extends SdchObserver {
-        private final ConditionVariable mBlock;
-
-        public DictionaryAddedObserver(String targetUrl, long contextAdapter) {
-            super(targetUrl, contextAdapter);
-            mBlock = new ConditionVariable();
-        }
-
-        @Override
-        public void onDictionaryAdded() {
-            mBlock.open();
-        }
-
-        public void waitForDictionaryAdded() {
-            if (!mDictionaryAlreadyPresent) {
-                mBlock.block();
-                mBlock.close();
-            }
-        }
-    }
-
     private long getContextAdapter(CronetUrlRequestContext requestContext) {
         return requestContext.getUrlRequestContextAdapter();
     }

components/cronet/android/test/src/org/chromium/net/SdchObserver.java

@@ -6,18 +6,19 @@
 
 import android.os.ConditionVariable;
 
+import junit.framework.Assert;
+
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
 
 /**
  * Class to watch for Sdch dictionary events. The native implementation
  * unregisters itself when an event happens. Therefore, an instance of this
  * class is only able to receive a notification of the earliest event.
- * Currently, implemented events include {@link #onDictionaryAdded}.
  */
 @JNINamespace("cronet")
 public class SdchObserver {
-    protected boolean mDictionaryAlreadyPresent = false;
+    private static final int BLOCK_WAIT_TIMEOUT_SEC = 20;
     private final ConditionVariable mAddBlock = new ConditionVariable();
 
     /**
@@ -27,29 +28,39 @@ public class SdchObserver {
      */
     public SdchObserver(String targetUrl, long contextAdapter) {
         nativeAddSdchObserver(targetUrl, contextAdapter);
-        mAddBlock.block();
-        mAddBlock.close();
     }
 
     /**
      * Called when a dictionary is added to the SdchManager for the target url.
-     * Override this method if caller would like to get notified.
      */
     @CalledByNative
-    public void onDictionaryAdded() {
-        // Left blank;
+    protected void onDictionaryAdded() {
+        mAddBlock.open();
     }
 
+    /**
+     * Called after the observer has been registered.
+     */
     @CalledByNative
-    private void onAddSdchObserverCompleted() {
-        mAddBlock.open();
+    protected void onAddSdchObserverCompleted() {
+        // Left blank;
     }
 
+    /**
+     * Called if the dictionary was added before the observer registration.
+     */
     @CalledByNative
-    private void onDictionarySetAlreadyPresent() {
-        mDictionaryAlreadyPresent = true;
+    protected void onDictionarySetAlreadyPresent() {
         mAddBlock.open();
     }
 
+    public void waitForDictionaryAdded() {
+        boolean success = mAddBlock.block(BLOCK_WAIT_TIMEOUT_SEC * 1000);
+        if (!success) {
+            Assert.fail("Timeout: the dictionary hasn't been added after waiting for "
+                    + BLOCK_WAIT_TIMEOUT_SEC + " seconds");
+        }
+    }
+
     private native void nativeAddSdchObserver(String targetUrl, long contextAdapter);
 }