cc: Interface to evict images from cc image decode cache.

cc/tiles/image_controller_unittest.cc

Index: cc/tiles/image_controller_unittest.cc
diff --git a/cc/tiles/image_controller_unittest.cc b/cc/tiles/image_controller_unittest.cc
index 034a59d500821c379fdf7480d392374e617f659c..ecc2cbb7c10791cc8a4c10d6cfd0ca3c915d89bc 100644
--- a/cc/tiles/image_controller_unittest.cc
+++ b/cc/tiles/image_controller_unittest.cc
@@ -129,6 +129,7 @@ class TestableCache : public ImageDecodeCache {
   void SetShouldAggressivelyFreeResources(
       bool aggressively_free_resources) override {}
   void ClearCache() override {}
+  void NotifyImageUnused(uint32_t skimage_id) override {}
   size_t GetMaximumMemoryLimitBytes() const override {
     return 256 * 1024 * 1024;
   }