GN(Android): Fix CleanupReferenceTest#testCreateMany failing.

content/public/android/javatests/src/org/chromium/content/common/CleanupReferenceTest.java

Index: content/public/android/javatests/src/org/chromium/content/common/CleanupReferenceTest.java
diff --git a/content/public/android/javatests/src/org/chromium/content/common/CleanupReferenceTest.java b/content/public/android/javatests/src/org/chromium/content/common/CleanupReferenceTest.java
index dc61afc0f18ed8c3045c468bf2761f3c057fad89..602d2f6b625873bacd9a3e8ced9300a7c0727b65 100644
--- a/content/public/android/javatests/src/org/chromium/content/common/CleanupReferenceTest.java
+++ b/content/public/android/javatests/src/org/chromium/content/common/CleanupReferenceTest.java
@@ -91,6 +91,9 @@ public class CleanupReferenceTest extends InstrumentationTestCase {
         instances = null;
         // Ensure compiler / instrumentation does not strip out the assignment.
         assertTrue(instances == null);
+        // Calling sObjectCount.get() before collectGarbage() seems to be required for the objects
+        // to be GC'ed only when building using GN.
+        assertTrue(sObjectCount.get() != -1);
         collectGarbage();
         assertTrue(CriteriaHelper.pollForCriteria(new Criteria() {
             @Override