Move DNS API to //extensions.

This was an easy target to move and it kills one more //chrome dep
from //extensions.

BUG=355752
TBR=rpaquay@chromium.org FYI for mechanical sockets changes

Review URL: https://codereview.chromium.org/209473012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@259199 0039d316-1c4b-4281-b951-d872f2087c98

9 files changed, 261 insertions, 2 deletions

diff --git a/extensions/browser/DEPS b/extensions/browser/DEPS
index 0060709..3ff0288 100644
--- a/extensions/browser/DEPS
+++ b/extensions/browser/DEPS
@@ -14,7 +14,6 @@ include_rules = [
   # TODO(jamescook): Remove these. http://crbug.com/162530
   "+chrome/browser/chrome_notification_types.h",
   "+chrome/browser/extensions/api/content_settings/content_settings_store.h",
-  "+chrome/browser/extensions/api/dns/host_resolver_wrapper.h",
   "+chrome/browser/extensions/api/preference/preference_api.h",
   "+chrome/browser/extensions/api/runtime/runtime_api.h",
   "+chrome/browser/renderer_host/chrome_render_message_filter.h",
diff --git a/extensions/browser/api/dns/dns_api.cc b/extensions/browser/api/dns/dns_api.cc
new file mode 100644
index 0000000..43ffc32
--- /dev/null
+++ b/extensions/browser/api/dns/dns_api.cc
@@ -0,0 +1,104 @@
+// 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 "extensions/browser/api/dns/dns_api.h"
+
+#include "base/bind.h"
+#include "base/values.h"
+#include "content/public/browser/browser_context.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/resource_context.h"
+#include "extensions/browser/api/dns/host_resolver_wrapper.h"
+#include "extensions/common/api/dns.h"
+#include "net/base/host_port_pair.h"
+#include "net/base/net_errors.h"
+#include "net/base/net_log.h"
+
+using content::BrowserThread;
+using extensions::core_api::dns::ResolveCallbackResolveInfo;
+
+namespace Resolve = extensions::core_api::dns::Resolve;
+
+namespace extensions {
+
+DnsResolveFunction::DnsResolveFunction()
+    : resource_context_(NULL),
+      response_(false),
+      request_handle_(new net::HostResolver::RequestHandle()),
+      addresses_(new net::AddressList) {}
+
+DnsResolveFunction::~DnsResolveFunction() {}
+
+bool DnsResolveFunction::RunImpl() {
+  scoped_ptr<Resolve::Params> params(Resolve::Params::Create(*args_));
+  EXTENSION_FUNCTION_VALIDATE(params.get());
+
+  hostname_ = params->hostname;
+  resource_context_ = browser_context()->GetResourceContext();
+
+  bool result = BrowserThread::PostTask(
+      BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(&DnsResolveFunction::WorkOnIOThread, this));
+  DCHECK(result);
+  return true;
+}
+
+void DnsResolveFunction::WorkOnIOThread() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  net::HostResolver* host_resolver =
+      HostResolverWrapper::GetInstance()->GetHostResolver(
+          resource_context_->GetHostResolver());
+  DCHECK(host_resolver);
+
+  // Yes, we are passing zero as the port. There are some interesting but not
+  // presently relevant reasons why HostResolver asks for the port of the
+  // hostname you'd like to resolve, even though it doesn't use that value in
+  // determining its answer.
+  net::HostPortPair host_port_pair(hostname_, 0);
+
+  net::HostResolver::RequestInfo request_info(host_port_pair);
+  int resolve_result = host_resolver->Resolve(
+      request_info,
+      net::DEFAULT_PRIORITY,
+      addresses_.get(),
+      base::Bind(&DnsResolveFunction::OnLookupFinished, this),
+      request_handle_.get(),
+      net::BoundNetLog());
+
+  // Balanced in OnLookupFinished.
+  AddRef();
+
+  if (resolve_result != net::ERR_IO_PENDING)
+    OnLookupFinished(resolve_result);
+}
+
+void DnsResolveFunction::RespondOnUIThread() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  SendResponse(response_);
+}
+
+void DnsResolveFunction::OnLookupFinished(int resolve_result) {
+  scoped_ptr<ResolveCallbackResolveInfo> resolve_info(
+      new ResolveCallbackResolveInfo());
+  resolve_info->result_code = resolve_result;
+  if (resolve_result == net::OK) {
+    DCHECK(!addresses_->empty());
+    resolve_info->address.reset(
+        new std::string(addresses_->front().ToStringWithoutPort()));
+  }
+  results_ = Resolve::Results::Create(*resolve_info);
+  response_ = true;
+
+  bool post_task_result = BrowserThread::PostTask(
+      BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(&DnsResolveFunction::RespondOnUIThread, this));
+  DCHECK(post_task_result);
+
+  Release();  // Added in WorkOnIOThread().
+}
+
+}  // namespace extensions
diff --git a/extensions/browser/api/dns/dns_api.h b/extensions/browser/api/dns/dns_api.h
new file mode 100644
index 0000000..f14769b
--- /dev/null
+++ b/extensions/browser/api/dns/dns_api.h
@@ -0,0 +1,52 @@
+// 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.
+
+#ifndef EXTENSIONS_BROWSER_API_DNS_DNS_API_H_
+#define EXTENSIONS_BROWSER_API_DNS_DNS_API_H_
+
+#include <string>
+
+#include "extensions/browser/extension_function.h"
+#include "net/base/address_list.h"
+#include "net/base/completion_callback.h"
+#include "net/dns/host_resolver.h"
+
+namespace content {
+class ResourceContext;
+}
+
+namespace extensions {
+
+class DnsResolveFunction : public AsyncExtensionFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION("dns.resolve", DNS_RESOLVE)
+
+  DnsResolveFunction();
+
+ protected:
+  virtual ~DnsResolveFunction();
+
+  // ExtensionFunction:
+  virtual bool RunImpl() OVERRIDE;
+
+  void WorkOnIOThread();
+  void RespondOnUIThread();
+
+ private:
+  void OnLookupFinished(int result);
+
+  std::string hostname_;
+
+  // Not owned.
+  content::ResourceContext* resource_context_;
+
+  bool response_;  // The value sent in SendResponse().
+
+  scoped_ptr<net::HostResolver::RequestHandle> request_handle_;
+  scoped_ptr<net::AddressList> addresses_;
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_BROWSER_API_DNS_DNS_API_H_
diff --git a/extensions/browser/api/dns/host_resolver_wrapper.cc b/extensions/browser/api/dns/host_resolver_wrapper.cc
new file mode 100644
index 0000000..f97a9c7
--- /dev/null
+++ b/extensions/browser/api/dns/host_resolver_wrapper.cc
@@ -0,0 +1,26 @@
+// 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 "extensions/browser/api/dns/host_resolver_wrapper.h"
+
+namespace extensions {
+
+HostResolverWrapper::HostResolverWrapper() : resolver_(NULL) {}
+
+// static
+HostResolverWrapper* HostResolverWrapper::GetInstance() {
+  return Singleton<extensions::HostResolverWrapper>::get();
+}
+
+net::HostResolver* HostResolverWrapper::GetHostResolver(
+    net::HostResolver* real_resolver) {
+  return resolver_ ? resolver_ : real_resolver;
+}
+
+void HostResolverWrapper::SetHostResolverForTesting(
+    net::HostResolver* mock_resolver) {
+  resolver_ = mock_resolver;
+}
+
+}  // namespace extensions
diff --git a/extensions/browser/api/dns/host_resolver_wrapper.h b/extensions/browser/api/dns/host_resolver_wrapper.h
new file mode 100644
index 0000000..4eb4282
--- /dev/null
+++ b/extensions/browser/api/dns/host_resolver_wrapper.h
@@ -0,0 +1,46 @@
+// 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.
+
+#ifndef EXTENSIONS_BROWSER_API_DNS_HOST_RESOLVER_WRAPPER_H_
+#define EXTENSIONS_BROWSER_API_DNS_HOST_RESOLVER_WRAPPER_H_
+
+#include "base/memory/singleton.h"
+#include "net/dns/host_resolver.h"
+
+namespace extensions {
+
+// Used for testing. In production code, this class does nothing interesting.
+// This class is a singleton that holds a pointer to a mock HostResolver, or
+// else to NULL. API classes that need to resolve hostnames ask this class for
+// the correct HostResolver to use, passing in the one that they want to use,
+// thereby avoiding most lifetime issues, and it will reply with either that
+// same one, or else the test version to use instead.
+//
+// This is a pretty complicated way to replace a single pointer with another.
+// TODO(miket): make the previous statement obsolete.
+class HostResolverWrapper {
+ public:
+  static HostResolverWrapper* GetInstance();
+
+  // Given a pointer to a real host resolver, returns the same pointer or else
+  // a substitute MockHostResolver to use instead. If
+  // SetHostResolverForTesting() hasn't been called, then this method returns
+  // the supplied argument as its result.
+  net::HostResolver* GetHostResolver(net::HostResolver* real_resolver);
+
+  // Sets the MockHostResolver to return in GetHostResolver().
+  void SetHostResolverForTesting(net::HostResolver* mock_resolver);
+
+ private:
+  HostResolverWrapper();
+  friend struct DefaultSingletonTraits<HostResolverWrapper>;
+
+  net::HostResolver* resolver_;
+
+  DISALLOW_COPY_AND_ASSIGN(HostResolverWrapper);
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_BROWSER_API_DNS_HOST_RESOLVER_WRAPPER_H_
diff --git a/extensions/browser/api/socket/socket_api.cc b/extensions/browser/api/socket/socket_api.cc
index dbe7a87..280e927c 100644
--- a/extensions/browser/api/socket/socket_api.cc
+++ b/extensions/browser/api/socket/socket_api.cc
@@ -8,9 +8,9 @@
 
 #include "base/bind.h"
 #include "base/containers/hash_tables.h"
-#include "chrome/browser/extensions/api/dns/host_resolver_wrapper.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/resource_context.h"
+#include "extensions/browser/api/dns/host_resolver_wrapper.h"
 #include "extensions/browser/api/socket/socket.h"
 #include "extensions/browser/api/socket/tcp_socket.h"
 #include "extensions/browser/api/socket/udp_socket.h"
diff --git a/extensions/common/api/api.gyp b/extensions/common/api/api.gyp
index 8297269..fb3c2b9 100644
--- a/extensions/common/api/api.gyp
+++ b/extensions/common/api/api.gyp
@@ -22,6 +22,7 @@
         ],
         # TODO: Eliminate these on Android. See crbug.com/305852.
         'schema_files': [
+          'dns.idl',
           'socket.idl',
           'sockets_tcp.idl',
           'sockets_tcp_server.idl',
diff --git a/extensions/common/api/dns.idl b/extensions/common/api/dns.idl
new file mode 100644
index 0000000..0500c0f
--- /dev/null
+++ b/extensions/common/api/dns.idl
@@ -0,0 +1,27 @@
+// 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.
+
+// Use the <code>chrome.dns</code> API for dns resolution.
+namespace dns {
+
+  dictionary ResolveCallbackResolveInfo {
+    // The result code. Zero indicates success.
+    long resultCode;
+
+    // A string representing the IP address literal. Supplied only if resultCode
+    // indicates success. Note that we presently return only IPv4 addresses.
+    DOMString? address;
+  };
+
+  callback ResolveCallback = void (ResolveCallbackResolveInfo resolveInfo);
+
+  interface Functions {
+    // Resolves the given hostname or IP address literal.
+    // |hostname| : The hostname to resolve.
+    // |callback| : Called when the resolution operation completes.
+    static void resolve(DOMString hostname,
+                        ResolveCallback callback);
+  };
+
+};
diff --git a/extensions/extensions.gyp b/extensions/extensions.gyp
index 2da4dc4..3319a5c 100644
--- a/extensions/extensions.gyp
+++ b/extensions/extensions.gyp
@@ -200,6 +200,10 @@
         'browser/api/api_resource_manager.h',
         'browser/api/async_api_function.cc',
         'browser/api/async_api_function.h',
+        'browser/api/dns/dns_api.cc',
+        'browser/api/dns/dns_api.h',
+        'browser/api/dns/host_resolver_wrapper.cc',
+        'browser/api/dns/host_resolver_wrapper.h',
         'browser/api/extensions_api_client.cc',
         'browser/api/extensions_api_client.h',
         'browser/api/socket/socket.cc',