Use no-op statistics collecting object for WebView

components/data_reduction_proxy/core/browser/data_reduction_proxy_statistics.cc

Index: components/data_reduction_proxy/core/browser/data_reduction_proxy_statistics.cc
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_statistics.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_statistics.cc
new file mode 100644
index 0000000000000000000000000000000000000000..de5e1fe954a199006daf88ea244a1b4317c7b8ae
--- /dev/null
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_statistics.cc
@@ -0,0 +1,29 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/data_reduction_proxy/core/browser/data_reduction_proxy_statistics.h"
+
+namespace data_reduction_proxy {
+DataReductionProxyStatistics::DataReductionProxyStatistics()
+    : list_value_(new base::ListValue) {
+}
+
+DataReductionProxyStatistics::~DataReductionProxyStatistics() {
+}
+
+int64 DataReductionProxyStatistics::GetInt64(const char*) {
+  return -1;
+}
+
+void DataReductionProxyStatistics::SetInt64(const char*, int64) {
+}
+
+base::ListValue* DataReductionProxyStatistics::GetList(const char*) {
+  return list_value_.get();

[bengr, 2014/10/17 23:40:27]

This seems very strange to me. Why not do what the derived class does and
maintain maps for lists and int64s to make this class functional? Then the
derived class can used these data structures instead of creating its own.

[hush (inactive), 2014/10/18 01:54:29]

Yes, I thought about this... WebView has to use a no-op
DataReductionProxyStatistics at the moment (otherwise we may need to have the
user's consent that WebView is gathering such data).

I can do what you said. But we need to make sure the WriteStats() function is
empty.
Since the data is already somewhere else in memory, I see no harm in putting it
to a map in memory. But we can't send it anywhere else (which is what WriteStats
does in the derived class)

+}
+
+void DataReductionProxyStatistics::WriteStats() {
+}
+
+}  // namespace data_reduction_proxy