Move gn _run target generation into test(). (RELAND)

third_party/WebKit/Source/platform/BUILD.gn

Index: third_party/WebKit/Source/platform/BUILD.gn
diff --git a/third_party/WebKit/Source/platform/BUILD.gn b/third_party/WebKit/Source/platform/BUILD.gn
index fd02572d094939cf9187901a720d8f7575879345..3ceedf8b9d9b0089b7f0dfe051621f352b0ce8c4 100644
--- a/third_party/WebKit/Source/platform/BUILD.gn
+++ b/third_party/WebKit/Source/platform/BUILD.gn
@@ -359,15 +359,6 @@ source_set("test_support") {
   }
 }
 
-# TODO(GYP): Delete this after we've converted everything to GN.
-# The _run targets exist only for compatibility w/ GYP.
-group("blink_heap_unittests_run") {
-  testonly = true
-  deps = [
-    ":blink_heap_unittests",
-  ]
-}
-
 # GYP: blink_heap_unittests
 test("blink_heap_unittests") {
   visibility = []  # Allow re-assignment of list.
@@ -402,15 +393,6 @@ test("blink_heap_unittests") {
   }
 }
 
-# TODO(GYP): Delete this after we've converted everything to GN.
-# The _run targets exist only for compatibility w/ GYP.
-group("blink_platform_unittests_run") {
-  testonly = true
-  deps = [
-    ":blink_platform_unittests",
-  ]
-}
-
 test("blink_platform_unittests") {
   visibility = []  # Allow re-assignment of list.
   visibility = [ "*" ]