Fix HotwordServiceTest under ubsan: no more vcalls on garbage.

chrome/browser/extensions/component_loader_unittest.cc

Index: chrome/browser/extensions/component_loader_unittest.cc
diff --git a/chrome/browser/extensions/component_loader_unittest.cc b/chrome/browser/extensions/component_loader_unittest.cc
index 5b21dd4b276e05790a93047bdde0c2db669e9c93..fcd3d68042a74988d56c2d49a6c5b6de8197d875 100644
--- a/chrome/browser/extensions/component_loader_unittest.cc
+++ b/chrome/browser/extensions/component_loader_unittest.cc
@@ -246,6 +246,8 @@ TEST_F(ComponentLoaderTest, LoadAll) {
   component_loader_.LoadAll();
 
   EXPECT_EQ(default_count + 1, registry->enabled_extensions().size());
+
+  base::MessageLoop::current()->RunUntilIdle();
 }
 
 TEST_F(ComponentLoaderTest, AddOrReplace) {
@@ -283,6 +285,7 @@ TEST_F(ComponentLoaderTest, AddOrReplace) {
   // Add an invalid component extension.
   std::string extension_id = component_loader_.AddOrReplace(invalid_extension);
   EXPECT_TRUE(extension_id.empty());
+  base::MessageLoop::current()->RunUntilIdle();
 }
 
 }  // namespace extensions