Add more control over sync for Chromium testshell.

chrome/android/java/src/org/chromium/chrome/browser/sync/ProfileSyncService.java

Index: chrome/android/java/src/org/chromium/chrome/browser/sync/ProfileSyncService.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/sync/ProfileSyncService.java b/chrome/android/java/src/org/chromium/chrome/browser/sync/ProfileSyncService.java
index f202ef7024e47d0b58cd4ec3dfa2f3ce562e4a53..4e846c0d8e860554c9dcb8e3a47106c55b76dba4 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/sync/ProfileSyncService.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/sync/ProfileSyncService.java
@@ -489,6 +489,16 @@ public class ProfileSyncService {
         nativeDisableSync(mNativeProfileSyncServiceAndroid);
     }
 
+    /**
+     * Returns the time when the last sync cycle was completed.
+     *
+     * @return The difference measured in microseconds, between last sync cycle completion time
+     * and 1 January 1970 00:00:00 UTC.
+     */
+    public long getLastSyncedTimeForTest() {
+        return nativeGetLastSyncedTimeForTest(mNativeProfileSyncServiceAndroid);
+    }
+
     // Native methods
     private native void nativeNudgeSyncer(
             int nativeProfileSyncServiceAndroid, String objectId, long version, String payload);
@@ -539,4 +549,5 @@ public class ProfileSyncService {
     private native boolean nativeHasKeepEverythingSynced(int nativeProfileSyncServiceAndroid);
     private native boolean nativeHasUnrecoverableError(int nativeProfileSyncServiceAndroid);
     private native String nativeGetAboutInfoForTest(int nativeProfileSyncServiceAndroid);
+    private native long nativeGetLastSyncedTimeForTest(int nativeProfileSyncServiceAndroid);
 }