Remove GTEST_HAS_COMBINE

This was removed from gtest and	is necessary to	roll gtest in
Chromium.

TBR=adamk@chromium.org

Bug: chromium:893369
Change-Id: I21762aa65ab2fc3f52731e7e812f0bf155f285e6
Reviewed-on: https://chromium-review.googlesource.com/c/1310598
Commit-Queue: Fabrice de Gans-Riberi <fdegans@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57193}

test/unittests/compiler/machine-operator-unittest.cc

@@ -13,8 +13,6 @@ namespace internal {
 namespace compiler {
 namespace machine_operator_unittest {
 
-#if GTEST_HAS_COMBINE
-
 template <typename T>
 class MachineOperatorTestWithParam
     : public TestWithZone,
@@ -159,7 +157,6 @@ INSTANTIATE_TEST_CASE_P(
         ::testing::Combine(::testing::ValuesIn(kRepresentationsForStore),
                            ::testing::Values(kNoWriteBarrier,
                                              kFullWriteBarrier))));
-#endif
 
 // -----------------------------------------------------------------------------
 // Pure operators.

test/unittests/compiler/regalloc/register-allocator-unittest.cc

@@ -711,8 +711,6 @@ class SlotConstraintTest : public RegisterAllocatorTest,
 
 }  // namespace
 
-#if GTEST_HAS_COMBINE
-
 TEST_P(SlotConstraintTest, SlotConstraint) {
   StartBlock();
   VReg p_0;
@@ -762,8 +760,6 @@ INSTANTIATE_TEST_CASE_P(
     ::testing::Combine(::testing::ValuesIn(kParameterTypes),
                        ::testing::Range(0, SlotConstraintTest::kMaxVariant)));
 
-#endif  // GTEST_HAS_COMBINE
-
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8