[net] Change factory methods for HostResolver and HostCache to return a scoped_ptr

net/base/host_resolver.cc

Index: net/base/host_resolver.cc
diff --git a/net/base/host_resolver.cc b/net/base/host_resolver.cc
index 3e86aff4165e2a6da71f18f6b0a1f8a1f5f907cb..38aefa1e38b060d1a11c45172fc9c8a128dc6be3 100644
--- a/net/base/host_resolver.cc
+++ b/net/base/host_resolver.cc
@@ -4,8 +4,23 @@
 
 #include "net/base/host_resolver.h"
 
+#include "net/base/host_cache.h"
+#include "net/base/host_resolver_impl.h"
+#include "net/dns/dns_client.h"
+#include "net/dns/dns_config_service.h"
+
 namespace net {
 
+namespace {
+// Maximum of 6 concurrent resolver threads (excluding retries).
+// Some routers (or resolvers) appear to start to provide host-not-found if
+// too many simultaneous resolutions are pending.  This number needs to be
+// further optimized, but 8 is what FF currently does. We found some routers
+// that limit this to 6, so we're temporarily holding it at that level.
+static const size_t kDefaultMaxProcTasks = 6u;
+
+}  // namespace
+
 HostResolver::RequestInfo::RequestInfo(const HostPortPair& host_port_pair)
     : host_port_pair_(host_port_pair),
       address_family_(ADDRESS_FAMILY_UNSPECIFIED),
@@ -33,6 +48,42 @@ base::Value* HostResolver::GetDnsConfigAsValue() const {
   return NULL;
 }
 
+// static
+scoped_ptr<HostResolver>
+HostResolver::CreateSystemResolver(size_t max_concurrent_resolves,

[cbentzel, 2012/08/17 13:41:52]

This used to be in host_resolver_impl.cc - and meant that this file did not
depend on the impl. Are you OK with this change?

+                                   size_t max_retry_attempts,
+                                   bool enable_cache,
+                                   bool enable_async,
+                                   NetLog* net_log) {
+  if (max_concurrent_resolves == kDefaultParallelism)
+    max_concurrent_resolves = kDefaultMaxProcTasks;
+
+  scoped_ptr<HostCache> cache(NULL);
+  if (enable_cache)
+    cache = HostCache::CreateDefaultCache();
+  scoped_ptr<DnsClient> dns_client(NULL);
+  if (enable_async)
+    dns_client = DnsClient::CreateClient(net_log);
+
+  return scoped_ptr<HostResolver>(new HostResolverImpl(
+      cache.Pass(),
+      PrioritizedDispatcher::Limits(NUM_PRIORITIES, max_concurrent_resolves),
+      HostResolverImpl::ProcTaskParams(NULL, max_retry_attempts),
+      DnsConfigService::CreateSystemService(),
+      dns_client.Pass(),
+      net_log));
+}
+
+// static
+scoped_ptr<HostResolver>
+HostResolver::CreateDefaultResolver(NetLog* net_log) {
+  return CreateSystemResolver(kDefaultParallelism,
+                              kDefaultRetryAttempts,
+                              true /* enable_cache */,
+                              false /* enable_async */,
+                              net_log);
+}
+
 HostResolver::HostResolver() {
 }