Revert "Revert "Clear the bitmap associated with canvases.""

This reverts commit 4e012846cd09caa85b018c36810e9a64adb87640.
diff --git a/src/com/android/launcher2/BubbleTextView.java b/src/com/android/launcher2/BubbleTextView.java
index 476d063..bd3a4bd 100644
--- a/src/com/android/launcher2/BubbleTextView.java
+++ b/src/com/android/launcher2/BubbleTextView.java
@@ -200,6 +200,7 @@
         canvas.setBitmap(b);
         drawWithPadding(canvas, padding);
         mOutlineHelper.applyExtraThickExpensiveOutlineWithBlur(b, canvas, glowColor, outlineColor);
+        canvas.setBitmap(null);
 
         return b;
     }