[Cleanup] Update histogram_tester.h includes in //net

Update all histogram_tester.h includes in //net to include
//base/test/metrics/histogram_tester.h

[email protected]

Bug: 846421
Change-Id: I8447f53256284fa4007345e054869e24d1c369dc
Reviewed-on: https://chromium-review.googlesource.com/1087290
Reviewed-by: Devlin <[email protected]>
Commit-Queue: Devlin <[email protected]>
Cr-Commit-Position: refs/heads/master@{#564573}
diff --git a/net/http/http_stream_factory_unittest.cc b/net/http/http_stream_factory_unittest.cc
index 72133c99d..79e374b 100644
--- a/net/http/http_stream_factory_unittest.cc
+++ b/net/http/http_stream_factory_unittest.cc
@@ -16,7 +16,7 @@
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/run_loop.h"
-#include "base/test/histogram_tester.h"
+#include "base/test/metrics/histogram_tester.h"
 #include "build/build_config.h"
 #include "net/base/completion_once_callback.h"
 #include "net/base/port_util.h"