ART: Refactor run-test 104

Ensure that the temporary list actually goes out of scope.

Test: art/test/testrunner/testrunner.py --host -b -t 104
Change-Id: Id258a7782ccfdf19e0fdc592a65490e0416b7b4c
diff --git a/test/104-growth-limit/src/Main.java b/test/104-growth-limit/src/Main.java
index d31cbf1..24acb91 100644
--- a/test/104-growth-limit/src/Main.java
+++ b/test/104-growth-limit/src/Main.java
@@ -21,7 +21,6 @@
 public class Main {
 
     public static void main(String[] args) throws Exception {
-        int alloc1 = 1;
         // Setup reflection stuff before allocating to prevent OOME caused by allocations from
         // Class.forName or getDeclaredMethod.
         // Reflective equivalent of: dalvik.system.VMRuntime.getRuntime().clearGrowthLimit();
@@ -29,34 +28,38 @@
         final Method get_runtime = vm_runtime.getDeclaredMethod("getRuntime");
         final Object runtime = get_runtime.invoke(null);
         final Method clear_growth_limit = vm_runtime.getDeclaredMethod("clearGrowthLimit");
-        List<byte[]> l = new ArrayList<byte[]>();
-        try {
-            while (true) {
-                // Allocate a MB at a time
-                l.add(new byte[1048576]);
-                alloc1++;
-            }
-        } catch (OutOfMemoryError e) {
-            l = null;
-        }
+
+        int alloc1 = allocateTillOOME();
+
+        // Proactively clean up.
+        Runtime.getRuntime().gc();
+
         // Expand the heap to the maximum size.
         clear_growth_limit.invoke(runtime);
-        int alloc2 = 1;
-        l = new ArrayList<byte[]>();
-        try {
-            while (true) {
-                // Allocate a MB at a time
-                l.add(new byte[1048576]);
-                alloc2++;
-            }
-        } catch (OutOfMemoryError e2) {
-            l = null;
-            if (alloc1 > alloc2) {
-                System.out.println("ERROR: Allocated less memory after growth" +
+
+        int alloc2 = allocateTillOOME();
+
+        if (alloc1 > alloc2) {
+            System.out.println("ERROR: Allocated less memory after growth" +
                     "limit cleared (" + alloc1 + " MBs > " + alloc2 + " MBs");
-                System.exit(1);
-            }
+        } else {
+            System.out.println("Test complete");
         }
-        System.out.println("Test complete");
+    }
+
+    private static int allocateTillOOME() {
+      int allocations = 0;
+      List<byte[]> l = new ArrayList<byte[]>();
+      try {
+          while (true) {
+              // Allocate a MB at a time
+              l.add(new byte[1048576]);
+              allocations++;
+          }
+      } catch (OutOfMemoryError e) {
+          // Help clean up.
+          l.clear();
+      }
+      return allocations;
     }
 }