resources: Prevent including the same resource in multiple pack files.

components/test/run_all_unittests.cc

Index: components/test/run_all_unittests.cc
diff --git a/components/test/run_all_unittests.cc b/components/test/run_all_unittests.cc
index 5cd4102f9f55014ecf5422a1ef4e9e39de409cb2..9b5962815c618e600d1a220fbe03fc32653d5c06 100644
--- a/components/test/run_all_unittests.cc
+++ b/components/test/run_all_unittests.cc
@@ -61,8 +61,14 @@ class ComponentsTestSuite : public base::TestSuite {
 #else
     PathService::Get(base::DIR_MODULE, &pak_path);
 #endif
-    ui::ResourceBundle::InitSharedInstanceWithPakPath(
-        pak_path.AppendASCII("components_tests_resources.pak"));
+
+    base::FilePath ui_test_pak_path;
+    ASSERT_TRUE(PathService::Get(ui::UI_TEST_PAK, &ui_test_pak_path));
+    ui::ResourceBundle::InitSharedInstanceWithPakPath(ui_test_pak_path);
+
+    ui::ResourceBundle::GetSharedInstance().AddDataPackFromPath(
+        pak_path.AppendASCII("components_tests_resources.pak"),
+        ui::SCALE_FACTOR_NONE);
 
     // These schemes need to be added globally to pass tests of
     // autocomplete_input_unittest.cc and content_settings_pattern*