[Trusted Types] Change sample string for Function Constructor.

Changed the CSP violation report sample string for Trusted
Types from `eval|(function anonymous(xxxx` to `Function|xxxx`.

Bug: 1048604
Change-Id: I6484ef73f78ea245d39efe219e30f5a0ed5d4f74
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2235621
Commit-Queue: Yifan Luo <lyf@chromium.org>
Reviewed-by: Daniel Vogelheim <vogelheim@chromium.org>
Cr-Commit-Position: refs/heads/master@{#776905}

third_party/blink/renderer/core/trustedtypes/trusted_types_util.cc

@@ -152,11 +152,19 @@ bool TrustedTypeFail(TrustedTypeViolationKind kind,
   if (execution_context->GetTrustedTypes())
     execution_context->GetTrustedTypes()->CountTrustedTypeAssignmentError();
 
+  const char* kAnonymousPrefix = "(function anonymous";
+  String prefix = GetSamplePrefix(exception_state);
+  if (prefix == "eval" && value.StartsWith(kAnonymousPrefix)) {
+    prefix = "Function";
+  }
   bool allow =
       execution_context->GetSecurityContext()
           .GetContentSecurityPolicy()
-          ->AllowTrustedTypeAssignmentFailure(GetMessage(kind), value,
-                                              GetSamplePrefix(exception_state));
+          ->AllowTrustedTypeAssignmentFailure(
+              GetMessage(kind),
+              prefix == "Function" ? value.Substring(strlen(kAnonymousPrefix))
+                                   : value,
+              prefix);
   if (!allow) {
     exception_state.ThrowTypeError(GetMessage(kind));
   }

third_party/blink/web_tests/external/wpt/content-security-policy/reporting/report-clips-sample.https.html

@@ -26,7 +26,7 @@
     });
     return waitUntilCSPEventForTrustedTypes(t).then(t.step_func_done(e => {
       assert_equals(e.sample.replace(/\n/g, ""),
-                    "eval|(function anonymous(a,b) {return '1234");
+                    "Function|(a,b) {return '12345678901234567890123");
     }));
   }, "Function constructor - the other kind of eval - is clipped.");