MSVC Build failures in 1.7.2

[drott]

https://logs.chromium.org/v/?s=chromium%2Fbb%2Ftryserver.chromium.win%2Fwin-msvc-rel%2F13269%2F%2B%2Frecipes%2Fsteps%2Fcompile__with_patch_%2F0%2Fstdout

FAILED: obj/third_party/harfbuzz-ng/harfbuzz_source/hb-ot-shape-complex-arabic.obj
ninja -t msvc -e environment.x64 -- E:\b\c\goma_client/gomacc.exe "e:\b\c\win_toolchain\vs_files\a9e1098bba66d2acccc377d5ee81265910f29272\vc\tools\msvc\14.11.25503\bin\hostx64\x64/cl.exe" /nologo /showIncludes @obj/third_party/harfbuzz-ng/harfbuzz_source/hb-ot-shape-complex-arabic.obj.rsp /c ../../third_party/harfbuzz-ng/src/hb-ot-shape-complex-arabic.cc /Foobj/third_party/harfbuzz-ng/harfbuzz_source/hb-ot-shape-complex-arabic.obj /Fd"obj/third_party/harfbuzz-ng/harfbuzz_source_cc.pdb"
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1176): error C2220: warning treated as error - no 'object' file generated
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1176): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1186): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1236): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1244): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1293): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1312): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1380): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1401): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1476): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1493): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1712): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1726): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1798): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1806): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1852): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1870): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1936): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(1961): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(2063): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsubgpos-private.hh(2085): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsub-table.hh(42): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsub-table.hh(56): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsub-table.hh(127): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsub-table.hh(141): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsub-table.hh(263): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsub-table.hh(271): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsub-table.hh(336): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsub-table.hh(350): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsub-table.hh(458): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsub-table.hh(476): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsub-table.hh(607): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsub-table.hh(617): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsub-table.hh(712): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsub-table.hh(720): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsub-table.hh(789): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsub-table.hh(803): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsub-table.hh(943): warning C4101: 'trace': unreferenced local variable
e:\b\c\b\win\src\third_party\harfbuzz-ng\src\hb-ot-layout-gsub-table.hh(972): warning C4101: 'trace': unreferenced local variable

[drott]

For a quick solution in Chrome, probably too broad, I did:

diff --git a/third_party/harfbuzz-ng/src/hb-private.hh b/third_party/harfbuzz-ng/src/hb-private.hh
index 9c55b4bc4b46..117f4983dc4f 100644
--- a/third_party/harfbuzz-ng/src/hb-private.hh
+++ b/third_party/harfbuzz-ng/src/hb-private.hh
@@ -112,6 +112,8 @@ extern "C" void  hb_free_impl(void *ptr);
 #endif
 #if __GNUC__ >= 4
 #define HB_UNUSED	__attribute__((unused))
+#elif defined(_MSC_VER)
+#define HB_UNUSED __pragma(warning(suppress: 4100 4101))
 #else
 #define HB_UNUSED
 #endif