Use QuicheTest in third_party/spdy.

Replace last two uses of testing::test with QuicheTest and replace single
gunit.h include with quiche_test.h.  Since this is the last gunit.h include in
all of QUICHE, remove substitution rule from third_party/quiche/copy.bara.sky.

PiperOrigin-RevId: 335054910
Change-Id: Ibfba8b4d60bc3fcdd7d3b87fb8d56fd6a3ad469c

spdy/core/spdy_intrusive_list_test.cc

diff --git a/spdy/core/spdy_intrusive_list_test.cc b/spdy/core/spdy_intrusive_list_test.cc
index e158d44..5f5243b 100644
--- a/spdy/core/spdy_intrusive_list_test.cc
+++ b/spdy/core/spdy_intrusive_list_test.cc
@@ -409,8 +409,7 @@
   }
 }
 
-
-class IntrusiveListTagTypeTest : public testing::Test {
+class IntrusiveListTagTypeTest : public QuicheTest {
  protected:
   struct Tag {};
   class Element : public SpdyIntrusiveLink<Element, Tag> {};

spdy/platform/api/spdy_mem_slice_test.cc

diff --git a/spdy/platform/api/spdy_mem_slice_test.cc b/spdy/platform/api/spdy_mem_slice_test.cc
index 84313b0..fa41b5e 100644
--- a/spdy/platform/api/spdy_mem_slice_test.cc
+++ b/spdy/platform/api/spdy_mem_slice_test.cc
@@ -6,17 +6,13 @@
 
 #include <utility>
 
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Weverything"
-
-#include "testing/gtest/include/gtest/gtest.h"
-#pragma clang diagnostic pop
+#include "net/third_party/quiche/src/common/platform/api/quiche_test.h"
 
 namespace spdy {
 namespace test {
 namespace {
 
-class SpdyMemSliceTest : public ::testing::Test {
+class SpdyMemSliceTest : public QuicheTest {
  public:
   SpdyMemSliceTest() {
     slice_ = SpdyMemSlice(1024);