Split clipboard unit test rule from blink/renderer/core:unit_tests.

Bug: 927857
Change-Id: I563d34e57c8589093878e792fe81ae71e6f2feaf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1531305
Commit-Queue: Aran Gilman <gilmanmh@google.com>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#642711}

third_party/blink/renderer/core/BUILD.gn

@@ -1706,8 +1706,6 @@ fuzzer_test("text_resource_decoder_fuzzer") {
 jumbo_source_set("unit_tests") {
   testonly = true
   sources = [
-    "clipboard/data_object_test.cc",
-    "clipboard/data_transfer_test.cc",
     "content_capture/content_capture_test.cc",
     "css/active_style_sheets_test.cc",
     "css/affected_by_pseudo_test.cc",
@@ -2245,6 +2243,7 @@ jumbo_source_set("unit_tests") {
     "//testing/gtest",
     "//third_party/blink/renderer/core/accessibility:unit_tests",
     "//third_party/blink/renderer/core/animation:unit_tests",
+    "//third_party/blink/renderer/core/clipboard:unit_tests",
     "//third_party/blink/renderer/core/editing:unit_tests",
     "//third_party/blink/renderer/core/fileapi:unit_tests",
   ]

third_party/blink/renderer/core/clipboard/BUILD.gn

@@ -36,3 +36,10 @@ blink_core_sources("clipboard") {
     "//ui/gfx/codec",
   ]
 }
+
+blink_core_tests("unit_tests") {
+  sources = [
+    "data_object_test.cc",
+    "data_transfer_test.cc",
+  ]
+}