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..1ed1da3bc375a6499b321c65a4fb753b3c9a0e2a 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.SchedulerBridgeInterface;
 
 /**
  * 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(
+            SchedulerBridgeInterface.ProcessingDoneCallback callback) {
         return nativeStartProcessing(callback);
     }
 
@@ -45,5 +39,14 @@ public class BackgroundSchedulerBridge {
         BackgroundScheduler.unschedule(ContextUtils.getApplicationContext());
     }
 
-    private static native boolean nativeStartProcessing(ProcessingDoneCallback callback);
+    /**
+     * Callback used to determine when request processing is done.
+     */
+    public interface ProcessingDoneCallback {

[dougarnett, 2016/06/02 00:14:45]

hmm, confusing to have same name for two interface definitions - hard to see
connection/use

[Pete Williamson, 2016/06/02 00:42:06]

Agreed, I'm playing tricks with JNI.  JNI needs to be able to see the definition
to be able for the C++ code to call it. It turns out I can only include one
XXX_jni.h file in the c++ code, so all the things needed to call into the bridge
need to be contained in the bridge file.  I made the declaration as identical as
possible to the SchedulerBridgeInterface definition so that a call to this can
act as a call to the other (duck typing).

If you'd like me to put that in a comment, let me know.  If you see a flaw in my
reasoning, let me know.

[dougarnett, 2016/06/02 16:31:47]

Yes, please try to document here.

[Pete Williamson, 2016/06/02 20:51:33]

Comment expanded.

+        @CalledByNative("ProcessingDoneCallback")
+        void onProcessingDone(boolean result);
+    }
+
+    private static native boolean nativeStartProcessing(
+            SchedulerBridgeInterface.ProcessingDoneCallback callback);
 }