[HttpCache] Store some memcache info to memory dumps for debugging

content/browser/cache_storage/cache_storage_cache_unittest.cc

Index: content/browser/cache_storage/cache_storage_cache_unittest.cc
diff --git a/content/browser/cache_storage/cache_storage_cache_unittest.cc b/content/browser/cache_storage/cache_storage_cache_unittest.cc
index 87898d3464fd033a805842bfea40da589041b6c5..9e2a305ef753e6a13dc65ba51025cd4035e6b9fe 100644
--- a/content/browser/cache_storage/cache_storage_cache_unittest.cc
+++ b/content/browser/cache_storage/cache_storage_cache_unittest.cc
@@ -118,9 +118,12 @@ class DelayableBackend : public disk_cache::Backend {
   void OnExternalCacheHit(const std::string& key) override {
     return backend_->OnExternalCacheHit(key);
   }
-  size_t EstimateMemoryUsage() const override {
+
+  size_t DumpMemoryStats(
+      base::trace_event::ProcessMemoryDump* pmd,
+      const std::string& parent_absolute_name) const override {
     NOTREACHED();
-    return 0;
+    return 0u;
   }
 
   // Call to continue a delayed doom.