Implement cache counting for the simple and memory backends.

net/disk_cache/simple/simple_backend_impl.cc

Index: net/disk_cache/simple/simple_backend_impl.cc
diff --git a/net/disk_cache/simple/simple_backend_impl.cc b/net/disk_cache/simple/simple_backend_impl.cc
index f985e58ae89f292cf7c46a6adce8cc296c7d5f88..d1c111eccf0372f7f35338cd6e750bd90dfd048e 100644
--- a/net/disk_cache/simple/simple_backend_impl.cc
+++ b/net/disk_cache/simple/simple_backend_impl.cc
@@ -442,19 +442,6 @@ int SimpleBackendImpl::DoomAllEntries(const CompletionCallback& callback) {
   return DoomEntriesBetween(Time(), Time(), callback);
 }
 
-void SimpleBackendImpl::IndexReadyForDoom(Time initial_time,
-                                          Time end_time,
-                                          const CompletionCallback& callback,
-                                          int result) {
-  if (result != net::OK) {
-    callback.Run(result);
-    return;
-  }
-  scoped_ptr<std::vector<uint64> > removed_key_hashes(
-      index_->GetEntriesBetween(initial_time, end_time).release());
-  DoomEntries(removed_key_hashes.get(), callback);
-}
-
 int SimpleBackendImpl::DoomEntriesBetween(
     const Time initial_time,
     const Time end_time,
@@ -472,8 +459,8 @@ int SimpleBackendImpl::DoomEntriesSince(
 
 int SimpleBackendImpl::CalculateSizeOfAllEntries(
     const CompletionCallback& callback) {
-  // TODO(msramek): Implement.
-  return net::ERR_NOT_IMPLEMENTED;
+  return index_->ExecuteWhenReady(base::Bind(
+      &SimpleBackendImpl::IndexReadyForSizeCalculation, AsWeakPtr(), callback));
 }
 
 class SimpleBackendImpl::SimpleIterator final : public Iterator {
@@ -570,6 +557,27 @@ void SimpleBackendImpl::InitializeIndex(const CompletionCallback& callback,
   callback.Run(result.net_error);
 }
 
+void SimpleBackendImpl::IndexReadyForDoom(Time initial_time,

[gavinp, 2015/10/14 15:08:06]

Thanks for cleaning this up.

+                                          Time end_time,
+                                          const CompletionCallback& callback,
+                                          int result) {
+  if (result != net::OK) {
+    callback.Run(result);
+    return;
+  }
+  scoped_ptr<std::vector<uint64>> removed_key_hashes(
+      index_->GetEntriesBetween(initial_time, end_time).release());
+  DoomEntries(removed_key_hashes.get(), callback);
+}
+
+void SimpleBackendImpl::IndexReadyForSizeCalculation(
+    const CompletionCallback& callback,
+    int result) {
+  if (result == net::OK)
+    result = static_cast<int>(index_->GetCacheSize());
+  callback.Run(result);
+}
+
 SimpleBackendImpl::DiskStatResult SimpleBackendImpl::InitCacheStructureOnDisk(
     const base::FilePath& path,
     uint64 suggested_max_size) {