[Suggestions UI] Drop Bitmap references from articles under memory pressure.

chrome/android/javatests/src/org/chromium/chrome/browser/ntp/snippets/ArticleSnippetsTest.java

Index: chrome/android/javatests/src/org/chromium/chrome/browser/ntp/snippets/ArticleSnippetsTest.java
diff --git a/chrome/android/javatests/src/org/chromium/chrome/browser/ntp/snippets/ArticleSnippetsTest.java b/chrome/android/javatests/src/org/chromium/chrome/browser/ntp/snippets/ArticleSnippetsTest.java
index 37a6b1f332d556b8297abeb2eab43541c4110737..160e41d0f26b97b055ea5f840823ea6959ef340d 100644
--- a/chrome/android/javatests/src/org/chromium/chrome/browser/ntp/snippets/ArticleSnippetsTest.java
+++ b/chrome/android/javatests/src/org/chromium/chrome/browser/ntp/snippets/ArticleSnippetsTest.java
@@ -4,12 +4,14 @@
 
 package org.chromium.chrome.browser.ntp.snippets;
 
+import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.support.test.filters.MediumTest;
 import android.util.TypedValue;
 import android.view.ViewGroup;
 import android.widget.FrameLayout;
 
+import org.chromium.base.ReferencePool;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.test.util.Feature;
 import org.chromium.base.test.util.RetryOnFailure;
@@ -133,8 +135,10 @@ public class ArticleSnippetsTest extends ChromeActivityTestCaseBase<ChromeActivi
                 1466614774, // Publish timestamp
                 10f, // Score
                 1466634774); // Fetch timestamp
-        shortSnippet.setThumbnailBitmap(BitmapFactory.decodeResource(getActivity().getResources(),
-                R.drawable.signin_promo_illustration));
+
+        Bitmap thumbnail = BitmapFactory.decodeResource(
+                getActivity().getResources(), R.drawable.signin_promo_illustration);
+        shortSnippet.setThumbnailBitmap(mUiDelegate.getReferencePool().put(thumbnail));
 
         SnippetArticle longSnippet = new SnippetArticle(fullCategory, "id2",
                 new String(new char[20]).replace("\0", "Snippet "),
@@ -197,6 +201,7 @@ public class ArticleSnippetsTest extends ChromeActivityTestCaseBase<ChromeActivi
         private SuggestionsEventReporter mSuggestionsEventReporter =
                 new DummySuggestionsEventReporter();
         private SuggestionsRanker mSuggestionsRanker = new SuggestionsRanker();
+        private final ReferencePool mReferencePool = new ReferencePool();
 
         @Override
         public void getLocalFaviconImageForURL(
@@ -235,6 +240,11 @@ public class ArticleSnippetsTest extends ChromeActivityTestCaseBase<ChromeActivi
             return mSuggestionsRanker;
         }
 
+        @Override
+        public ReferencePool getReferencePool() {
+            return mReferencePool;
+        }
+
         @Override
         public void addDestructionObserver(DestructionObserver destructionObserver) {}