Remove usage of Tab's |url| property from TabUsageRecorder.

BUG=546208

Review-Url: https://codereview.chromium.org/2820763002
Cr-Commit-Position: refs/heads/master@{#476528}
diff --git a/ios/chrome/browser/metrics/BUILD.gn b/ios/chrome/browser/metrics/BUILD.gn
index 3ac24ce..feff38a2 100644
--- a/ios/chrome/browser/metrics/BUILD.gn
+++ b/ios/chrome/browser/metrics/BUILD.gn
@@ -147,6 +147,7 @@
     "//ios/testing:ocmock_support",
     "//ios/web",
     "//ios/web/public/test",
+    "//ios/web/public/test/fakes",
     "//testing/gtest",
     "//third_party/ocmock",
   ]