Ensures that selection test data files are non-empty on the bots by adding...

Ensures that selection test data files are non-empty on the bots by adding data dependency to the BUILD file

In case the files are somehow not found or unreadable on the bots, the tests should fail.
R=dmazzoni@chromium.org

Change-Id: I31668ab7a1b023a9eeda251b3ae0e7079f262171
Reviewed-on: https://chromium-review.googlesource.com/c/1324232Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: Nektarios Paisios <nektar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606858}

third_party/blink/renderer/modules/BUILD.gn

@@ -374,4 +374,14 @@ jumbo_source_set("unit_tests") {
     "//third_party/webrtc/rtc_base:rtc_base",
     "//v8",
   ]
+
+  data_deps = [
+    ":accessibility_unittests_data",
+  ]
+}
+
+group("accessibility_unittests_data") {
+  data = [
+    "accessibility/testing/data/",
+  ]
 }

third_party/blink/renderer/modules/accessibility/testing/accessibility_selection_test.cc

@@ -393,6 +393,10 @@ void AccessibilitySelectionTest::RunSelectionTest(
   std::string test_file_contents;
   std::copy(test_file_chars.begin(), test_file_chars.end(),
             std::back_inserter(test_file_contents));
+  ASSERT_FALSE(test_file_contents.empty())
+      << "Test file cannot be empty.\n"
+      << test_file.Utf8().data()
+      << "\nDid you forget to add a data dependency to the BUILD file?";
 
   const String ax_file = test_path + String::FromUTF8(kAXTestExpectationSuffix);
   scoped_refptr<SharedBuffer> ax_file_buffer = ReadFromFile(ax_file);
@@ -400,6 +404,10 @@ void AccessibilitySelectionTest::RunSelectionTest(
   std::string ax_file_contents;
   std::copy(ax_file_chars.begin(), ax_file_chars.end(),
             std::back_inserter(ax_file_contents));
+  ASSERT_FALSE(ax_file_contents.empty())
+      << "Expectations file cannot be empty.\n"
+      << ax_file.Utf8().data()
+      << "\nDid you forget to add a data dependency to the BUILD file?";
 
   HTMLElement* body = GetDocument().body();
   ASSERT_NE(nullptr, body);