Fix memory leak in (Begin atlasing  https://codereview.chromium.org/354533004/)

R=bsalomon@google.com
TBR=bsalomon@google.com

Author: robertphillips@google.com

Review URL: https://codereview.chromium.org/361663002
diff --git a/src/gpu/GrLayerCache.cpp b/src/gpu/GrLayerCache.cpp
index 5f657c7..eb0cc8a 100644
--- a/src/gpu/GrLayerCache.cpp
+++ b/src/gpu/GrLayerCache.cpp
@@ -47,6 +47,7 @@
 }
 
 GrLayerCache::~GrLayerCache() {
+    this->freeAll();
 }
 
 void GrLayerCache::initAtlas() {