Clear thumb loads when full load finishes.

library/src/androidTest/java/com/bumptech/glide/request/ThumbnailRequestCoordinatorTest.java

@@ -2,6 +2,7 @@ package com.bumptech.glide.request;
 
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
+import static org.mockito.Matchers.any;
 import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.inOrder;
 import static org.mockito.Mockito.mock;
@@ -266,4 +267,40 @@ public class ThumbnailRequestCoordinatorTest {
         assertTrue(coordinator.isResourceSet());
     }
 
+    @Test
+    public void testClearsThumbRequestOnFullRequestComplete_withNullParent() {
+        coordinator.onRequestSuccess(full);
+        verify(thumb).clear();
+    }
+
+    @Test
+    public void testNotifiesParentOnFullRequestComplete_withNonNullParent() {
+        coordinator = new ThumbnailRequestCoordinator(parent);
+        coordinator.setRequests(full, thumb);
+        coordinator.onRequestSuccess(full);
+        verify(parent).onRequestSuccess(eq(coordinator));
+    }
+
+    @Test
+    public void testDoesNotClearThumbRequestOnFullRequestComplete_withNonNullParent() {
+        coordinator = new ThumbnailRequestCoordinator(parent);
+        coordinator.setRequests(full, thumb);
+        coordinator.onRequestSuccess(full);
+        verify(thumb, never()).clear();
+    }
+
+    @Test
+    public void testDoesNotClearThumbOnThumbRequestComplete() {
+        coordinator.onRequestSuccess(thumb);
+        verify(thumb, never()).clear();
+    }
+
+    @Test
+    public void testDoesNotNotifyParentOnThumbRequestComplete() {
+        coordinator = new ThumbnailRequestCoordinator(parent);
+        coordinator.setRequests(full, thumb);
+        coordinator.onRequestSuccess(thumb);
+
+        verify(parent, never()).onRequestSuccess(any(Request.class));
+    }
 }

library/src/main/java/com/bumptech/glide/request/GenericRequest.java

@@ -438,6 +438,12 @@ public final class GenericRequest<A, T, Z, R> implements Request, SizeReadyCallb
         return requestCoordinator == null || !requestCoordinator.isAnyResourceSet();
     }
 
+    private void notifyLoadSuccess() {
+      if (requestCoordinator != null) {
+        requestCoordinator.onRequestSuccess(this);
+      }
+    }
+
     /**
      * A callback method that should never be invoked directly.
      */
@@ -488,6 +494,7 @@ public final class GenericRequest<A, T, Z, R> implements Request, SizeReadyCallb
 
         status = Status.COMPLETE;
         this.resource = resource;
+        notifyLoadSuccess();
 
         if (Log.isLoggable(TAG, Log.VERBOSE)) {
             logV("Resource ready in " + LogTime.getElapsedMillis(startTime) + " size: "

library/src/main/java/com/bumptech/glide/request/RequestCoordinator.java

@@ -25,4 +25,9 @@ public interface RequestCoordinator {
      * @see Request#isComplete()
      */
     boolean isAnyResourceSet();
+
+    /**
+     * Must be called when a request coordinated by this object completes successfully.
+     */
+    void onRequestSuccess(Request request);
 }

library/src/main/java/com/bumptech/glide/request/ThumbnailRequestCoordinator.java

@@ -58,6 +58,18 @@ public class ThumbnailRequestCoordinator implements RequestCoordinator, Request
         return parentIsAnyResourceSet() || isResourceSet();
     }
 
+    @Override
+    public void onRequestSuccess(Request request) {
+      if (request.equals(thumb)) {
+        return;
+      }
+      if (coordinator == null) {
+        thumb.clear();
+      } else {
+        coordinator.onRequestSuccess(this);
+      }
+    }
+
     private boolean parentIsAnyResourceSet() {
         return coordinator != null && coordinator.isAnyResourceSet();
     }