Move histogram to test/core/util
diff --git a/grpc.gyp b/grpc.gyp
index f2033b4..4ceb480 100644
--- a/grpc.gyp
+++ b/grpc.gyp
@@ -173,7 +173,6 @@
         'src/core/lib/support/env_posix.cc',
         'src/core/lib/support/env_windows.cc',
         'src/core/lib/support/fork.cc',
-        'src/core/lib/support/histogram.cc',
         'src/core/lib/support/host_port.cc',
         'src/core/lib/support/log.cc',
         'src/core/lib/support/log_android.cc',
@@ -506,6 +505,7 @@
         'test/core/iomgr/endpoint_tests.cc',
         'test/core/util/debugger_macros.cc',
         'test/core/util/grpc_profiler.cc',
+        'test/core/util/histogram.cc',
         'test/core/util/memory_counters.cc',
         'test/core/util/mock_endpoint.cc',
         'test/core/util/parse_hexstring.cc',
@@ -716,6 +716,7 @@
         'test/core/iomgr/endpoint_tests.cc',
         'test/core/util/debugger_macros.cc',
         'test/core/util/grpc_profiler.cc',
+        'test/core/util/histogram.cc',
         'test/core/util/memory_counters.cc',
         'test/core/util/mock_endpoint.cc',
         'test/core/util/parse_hexstring.cc',