Add unit tests for the Background Scheduler.

chrome/android/java/src/org/chromium/chrome/browser/offlinepages/BackgroundSchedulerBridge.java

Index: chrome/android/java/src/org/chromium/chrome/browser/offlinepages/BackgroundSchedulerBridge.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/BackgroundSchedulerBridge.java b/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/BackgroundSchedulerBridge.java
index aaf8ab98679adbaaa455989eb55112c2c0a3b65b..08b02f6d8399b4d0ee00bc72965b4908c08e4297 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/BackgroundSchedulerBridge.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/BackgroundSchedulerBridge.java
@@ -7,6 +7,7 @@ package org.chromium.chrome.browser.offlinepages;
 import org.chromium.base.ContextUtils;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
+import org.chromium.chrome.browser.offlinepages.interfaces.SchedulerBridge;
 
 /**
  * Provides Java scheduling support from native offlining code as
@@ -15,14 +16,6 @@ import org.chromium.base.annotations.JNINamespace;
  */
 @JNINamespace("offline_pages::android")
 public class BackgroundSchedulerBridge {
-    /**
-     * Callback used to determine when request processing is done.
-     */
-    public interface ProcessingDoneCallback {
-        @CalledByNative("ProcessingDoneCallback")
-        void onProcessingDone(boolean result);
-    }
-
     // Starts processing of one or more queued background requests.
     // Returns whether processing was started and that caller should
     // expect a callback (once processing has completed or terminated).
@@ -31,7 +24,8 @@ public class BackgroundSchedulerBridge {
     // not receive a callback.
     // TODO(dougarnett): consider adding policy check api to let caller
     //     separately determine if not allowed by policy.
-    public static boolean startProcessing(ProcessingDoneCallback callback) {
+    public static boolean startProcessing(
+            SchedulerBridge.ProcessingDoneCallback callback) {
         return nativeStartProcessing(callback);
     }
 
@@ -45,5 +39,20 @@ public class BackgroundSchedulerBridge {
         BackgroundScheduler.unschedule(ContextUtils.getApplicationContext());
     }
 
-    private static native boolean nativeStartProcessing(ProcessingDoneCallback callback);
+    /**
+     * This interface defines the JNI callback available to native code. It must exactly match the
+     * {@link SchedulerBridge.ProcessingDoneCallback} interface (which is not tied to JNI and may be
+     * use for unit testing).  Due to JNI restrictions, the interface for this callback must be
+     * declared in the same java file, so there is only one XXX_jni.h file to include on the C++
+     * side (Otherwise, we get the JNI function RegisterNativesImpl multiply defined, and can't
+     * compile). This interface is exactly the same as the one in SchedulerBridge, and we're using
+     * duck typing to make sure the callback can work.
+     */
+    public interface ProcessingDoneCallback {
+        @CalledByNative("ProcessingDoneCallback")
+        void onProcessingDone(boolean result);
+    }
+
+    private static native boolean nativeStartProcessing(
+            SchedulerBridge.ProcessingDoneCallback callback);
 }