partition_alloc: Run DanglingPointerTest only in dawn_standalone.

dawn_unittests are run in both Dawn and Chrome repository. This is
problematic for this test. Indeed, dawn and chrome are configuring
partition_alloc differently.

For instance:
- Chrome displays a different error message.
- Chrome reconfigures partition_alloc differently after forking the
  process. This matters in gtest's DEATH_TEST.
- Chrome have a more complex configuration depending on the OS and build
  configuration.

Bug: None
Change-Id: I7cf2a6ef1137b4991e67f9640d103878c564d2cd
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/169180
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>
Auto-Submit: Arthur Sonzogni <arthursonzogni@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
diff --git a/src/dawn/tests/BUILD.gn b/src/dawn/tests/BUILD.gn
index c9fa2fd..6759054 100644
--- a/src/dawn/tests/BUILD.gn
+++ b/src/dawn/tests/BUILD.gn
@@ -340,7 +340,6 @@
     "unittests/PerThreadProcTests.cpp",
     "unittests/PlacementAllocatedTests.cpp",
     "unittests/RangeTests.cpp",
-    "unittests/RawPtrTests.cpp",
     "unittests/RefBaseTests.cpp",
     "unittests/RefCountedTests.cpp",
     "unittests/ResultTests.cpp",
@@ -441,6 +440,13 @@
     "unittests/wire/WireTest.h",
   ]
 
+  # `dawn_unittests` are known to run for both Dawn standalone and Chrome. This
+  # file is testing specifically the Dawn's standalone configuration of
+  # partition_alloc.
+  if (dawn_standalone) {
+    sources += [ "unittests/RawPtrTests.cpp" ]
+  }
+
   if (is_win) {
     sources += [ "unittests/WindowsUtilsTests.cpp" ]
   }