Fix unit test failure

Author: jerryshao

core/src/main/scala/org/apache/spark/storage/BlockManager.scala

@@ -803,7 +803,7 @@ private[spark] class BlockManager(
       val putBlockStatus = getCurrentBlockStatus(blockId, info)
       val blockWasSuccessfullyStored = putBlockStatus.storageLevel.isValid
       if (blockWasSuccessfullyStored) {
-        // Now that the block is in either the memory, externalBlockStore, or disk store,
+        // Now that the block is in either the memory or disk store,
         // tell the master about it.
         info.size = size
         if (tellMaster) {

core/src/test/scala/org/apache/spark/memory/TestMemoryManager.scala

@@ -56,6 +56,8 @@ class TestMemoryManager(conf: SparkConf)
   }
   override def maxOnHeapStorageMemory: Long = Long.MaxValue
 
+  override def maxOffHeapStorageMemory: Long = 0L
+
   private var oomOnce = false
   private var available = Long.MaxValue
 

core/src/test/scala/org/apache/spark/storage/BlockManagerSuite.scala

@@ -239,8 +239,8 @@ class BlockManagerSuite extends SparkFunSuite with Matchers with BeforeAndAfterE
 
     // Checking whether blocks are in memory and memory size
     val memStatus = master.getMemoryStatus.head._2
-    assert(memStatus._1 == 20000L, "total memory " + memStatus._1 + " should equal 20000")
-    assert(memStatus._2 <= 12000L, "remaining memory " + memStatus._2 + " should <= 12000")
+    assert(memStatus._1 == 40000L, "total memory " + memStatus._1 + " should equal 40000")
+    assert(memStatus._2 <= 32000L, "remaining memory " + memStatus._2 + " should <= 12000")
     assert(store.getSingleAndReleaseLock("a1-to-remove").isDefined, "a1 was not in store")
     assert(store.getSingleAndReleaseLock("a2-to-remove").isDefined, "a2 was not in store")
     assert(store.getSingleAndReleaseLock("a3-to-remove").isDefined, "a3 was not in store")
@@ -269,8 +269,8 @@ class BlockManagerSuite extends SparkFunSuite with Matchers with BeforeAndAfterE
     }
     eventually(timeout(1000 milliseconds), interval(10 milliseconds)) {
       val memStatus = master.getMemoryStatus.head._2
-      memStatus._1 should equal (20000L)
-      memStatus._2 should equal (20000L)
+      memStatus._1 should equal (40000L)
+      memStatus._2 should equal (40000L)
     }
   }