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..382cf4c158582595a391f6c156aeb2662acc3e88 100644
--- a/net/disk_cache/simple/simple_backend_impl.cc
+++ b/net/disk_cache/simple/simple_backend_impl.cc
@@ -470,10 +470,20 @@ int SimpleBackendImpl::DoomEntriesSince(
   return DoomEntriesBetween(initial_time, Time(), callback);
 }
 
+void SimpleBackendImpl::IndexReadyForCalculation(

[gavinp, 2015/10/13 15:50:12]

Isn't this an ordering violation? See
https://google-styleguide.googlecode.com/svn/trunk/cppguide.html#Declaration_...

[msramek, 2015/10/13 17:25:50]

Yep. I tried to follow IndexReadyForDoom, but that one was already misplaced.

+    const CompletionCallback& callback,
+    int result) {
+  if (result == net::OK)
+    result = static_cast<int>(index_->GetCacheSize());
+  callback.Run(result);
+}
+
 int SimpleBackendImpl::CalculateSizeOfAllEntries(
     const CompletionCallback& callback) {
-  // TODO(msramek): Implement.
-  return net::ERR_NOT_IMPLEMENTED;
+  return index_->ExecuteWhenReady(
+      base::Bind(&SimpleBackendImpl::IndexReadyForCalculation,
+                 AsWeakPtr(),
+                 callback));

[gavinp, 2015/10/13 15:50:12]

Did git cl format not join these lines? Weird...

[msramek, 2015/10/13 17:25:50]

Ehm, I didn't run it.

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

We're very diligent about that in net/. Generally if you're not going to run it,
please file a bug against git cl format (I believe tag is Build-Tools) for the
specific problem you're working around.

[msramek, 2015/10/14 16:11:58]

Acknowledged.

 }
 
 class SimpleBackendImpl::SimpleIterator final : public Iterator {