Merge pull request #16011 from adelez/foundry2

Step 3 of multipool RBE configuration.
diff --git a/test/core/gpr/BUILD b/test/core/gpr/BUILD
index 5308ea0..d58d4f2 100644
--- a/test/core/gpr/BUILD
+++ b/test/core/gpr/BUILD
@@ -86,6 +86,7 @@
         "//:gpr",
         "//test/core/util:gpr_test_util",
     ],
+    data = ["//third_party/toolchains:RBE_USE_MACHINE_TYPE_LARGE"],
 )
 
 grpc_cc_test(
diff --git a/test/core/iomgr/BUILD b/test/core/iomgr/BUILD
index cc1b6ae..fb0490a 100644
--- a/test/core/iomgr/BUILD
+++ b/test/core/iomgr/BUILD
@@ -47,6 +47,7 @@
         "//test/core/util:gpr_test_util",
         "//test/core/util:grpc_test_util",
     ],
+    data = ["//third_party/toolchains:RBE_USE_MACHINE_TYPE_LARGE"],
 )
 
 grpc_cc_test(
diff --git a/test/cpp/qps/BUILD b/test/cpp/qps/BUILD
index a348b88..e7d093c 100644
--- a/test/cpp/qps/BUILD
+++ b/test/cpp/qps/BUILD
@@ -176,6 +176,7 @@
         "//test/cpp/util:test_config",
         "//test/cpp/util:test_util",
     ],
+    data = ["//third_party/toolchains:RBE_USE_MACHINE_TYPE_LARGE"],
 )
 
 grpc_cc_test(
diff --git a/third_party/toolchains/BUILD b/third_party/toolchains/BUILD
index 1933072..29fc4fd 100644
--- a/third_party/toolchains/BUILD
+++ b/third_party/toolchains/BUILD
@@ -16,6 +16,8 @@
 
 package(default_visibility = ["//visibility:public"])
 
+exports_files(["RBE_USE_MACHINE_TYPE_LARGE",])
+
 # Latest RBE Ubuntu16_04 container
 # Update every time when a new container is released.
 alias(
@@ -39,8 +41,12 @@
           value:"docker://gcr.io/cloud-marketplace/google/rbe-ubuntu16-04@sha256:59bf0e191a6b5cc1ab62c2224c810681d1326bad5a27b1d36c9f40113e79da7f"
         }
         properties: {
-          name: "gceMachineType"
-          value: "n1-highmem-2"
+          name: "gceMachineType"  # Small machines for majority of tests.
+          value: "n1-standard-1"
+        }
+        properties: {
+          name: "gceMachineType_LARGE"  # Large machines for a small set of resource-consuming tests such as combiner_tests under TSAN.
+          value: "n1-standard-8"
         }
         """,
 )
diff --git a/third_party/toolchains/RBE_USE_MACHINE_TYPE_LARGE b/third_party/toolchains/RBE_USE_MACHINE_TYPE_LARGE
new file mode 100644
index 0000000..b112023
--- /dev/null
+++ b/third_party/toolchains/RBE_USE_MACHINE_TYPE_LARGE
@@ -0,0 +1 @@
+# This file is a sentinel and is meant to be empty.