Allow socket creation to be delegated from sandbox target to broker.

This is needed to allow connections to loopback from within
an App Container on Windows. See
https://docs.microsoft.com/en-us/windows/iot-core/develop-your-app/loopback

Only overlapped sockets are supported by the broker, as these
are the only ones used by Chromium.

Add tests to verify this works for both UDP and TCP sockets. Since
this code can't depend on net/ a very simple UDP server is used
for testing.

BUG=841001

Change-Id: I794bdadb779b456c5dba97d01d3e646b793ad265
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3069722
Reviewed-by: Alex Gough <ajgo@chromium.org>
Reviewed-by: Daniel Rubery <drubery@chromium.org>
Commit-Queue: Will Harris <wfh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#909354}

chrome/chrome_cleaner/ipc/sandbox_unittest.cc

@@ -26,6 +26,7 @@
 #include "chrome/chrome_cleaner/logging/scoped_logging.h"
 #include "chrome/chrome_cleaner/os/disk_util.h"
 #include "chrome/chrome_cleaner/os/initializer.h"
+#include "sandbox/win/src/sandbox.h"
 #include "sandbox/win/src/sandbox_factory.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -46,6 +47,7 @@ class MockSandboxTargetServices : public sandbox::TargetServices {
   MOCK_METHOD0(Init, sandbox::ResultCode());
   MOCK_METHOD0(LowerToken, void());
   MOCK_METHOD0(GetState, sandbox::ProcessState*());
+  MOCK_METHOD3(CreateBrokeredSocket, SOCKET(int af, int family, int protocol));
 };
 
 class TestSandboxSetupHooks : public SandboxSetupHooks {

sandbox/win/BUILD.gn

@@ -127,6 +127,8 @@ static_library("sandbox") {
     "src/signed_interception.h",
     "src/signed_policy.cc",
     "src/signed_policy.h",
+    "src/socket_dispatcher.cc",
+    "src/socket_dispatcher.h",
     "src/startup_information_helper.cc",
     "src/startup_information_helper.h",
     "src/sync_dispatcher.cc",
@@ -239,7 +241,10 @@ test("sbox_integration_tests") {
     ":sbox_integration_test_win_proc",
   ]
 
-  libs = [ "ktmw32.lib" ]
+  libs = [
+    "ktmw32.lib",
+    "iphlpapi.lib",
+  ]
 }
 
 shared_library("sbox_integration_test_hijack_dll") {

sandbox/win/fuzzer/fuzzer_types.h

@@ -32,6 +32,7 @@ typedef uint32_t ULONG;
 typedef uint32_t* ULONG_PTR;
 typedef LONG NTSTATUS;
 typedef void PROCESS_INFORMATION;
+typedef uintptr_t SOCKET;
 
 // __stdcall is used in one place. TODO(wfh): replace with WINAPI.
 #define __stdcall