Made setting lowbox token a warning.

content/common/sandbox_win.cc

Index: content/common/sandbox_win.cc
diff --git a/content/common/sandbox_win.cc b/content/common/sandbox_win.cc
index 35c33d597cc2a730df0c55f89cfa67fb6ea27f5f..9db2a3838622870611566dcb118e1e60421d9772 100644
--- a/content/common/sandbox_win.cc
+++ b/content/common/sandbox_win.cc
@@ -797,9 +797,11 @@ sandbox::ResultCode StartSandboxedProcess(
   TRACE_EVENT_BEGIN0("startup", "StartProcessWithAccess::LAUNCHPROCESS");
 
   PROCESS_INFORMATION temp_process_info = {};
-  result = g_broker_services->SpawnTarget(
-      cmd_line->GetProgram().value().c_str(),
-      cmd_line->GetCommandLineString().c_str(), policy, &temp_process_info);
+  sandbox::ResultCode last_warning = sandbox::SBOX_ALL_OK;
+  result =
+      g_broker_services->SpawnTarget(cmd_line->GetProgram().value().c_str(),
+                                     cmd_line->GetCommandLineString().c_str(),
+                                     policy, &last_warning, &temp_process_info);
   DWORD last_error = ::GetLastError();

[Will Harris, 2016/07/12 16:10:59]

Seems anachronistic to pass the last_error by SetLastError() and GetLastError()
but pass last_warning via param, I wonder if this code could be changed in a
future CL.

   base::win::ScopedProcessInformation target(temp_process_info);
 
@@ -815,6 +817,12 @@ sandbox::ResultCode StartSandboxedProcess(
     return result;
   }
 
+  if (sandbox::SBOX_ALL_OK != last_warning) {
+    UMA_HISTOGRAM_SPARSE_SLOWLY("Process.Sandbox.Launch.WarningResultCode",

[Will Harris, 2016/07/12 16:10:59]

it might be an idea to always log this first histogram even when last_warning is
SBOX_ALL_OK then we get an accurate bucket percentage for each type.

+                                last_warning);
+    UMA_HISTOGRAM_SPARSE_SLOWLY("Process.Sandbox.Launch.Warning", last_error);
+  }
+
   delegate->PostSpawnTarget(target.process_handle());
 
   CHECK(ResumeThread(target.thread_handle()) != static_cast<DWORD>(-1));