reapply r70628. It was wrongly blamed for breaking Linux valgrind bots.

net/url_request/view_cache_helper_unittest.cc

Index: net/url_request/view_cache_helper_unittest.cc
diff --git a/net/url_request/view_cache_helper_unittest.cc b/net/url_request/view_cache_helper_unittest.cc
index 5338ee597a99d15b44b8ca599480395f4623cc7a..3903c2b5f5fc53e392ecc310d3a56267fffa8aa5 100644
--- a/net/url_request/view_cache_helper_unittest.cc
+++ b/net/url_request/view_cache_helper_unittest.cc
@@ -25,7 +25,7 @@ class TestURLRequestContext : public URLRequestContext {
 };
 
 TestURLRequestContext::TestURLRequestContext()
-    : cache_(reinterpret_cast<net::HttpTransactionFactory*>(NULL),
+    : cache_(reinterpret_cast<net::HttpTransactionFactory*>(NULL), NULL,
              net::HttpCache::DefaultBackend::InMemory(0)) {
   http_transaction_factory_ = &cache_;
 }