WebUI tests: Remove no longer necessary unsafe-eval token from CSP.

Bug: 844820,525224
Change-Id: I6f2f40c2dd7e03a570eba8e08654eb38c9897776
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2586100
Commit-Queue: Rebekah Potter <rbpotter@chromium.org>
Auto-Submit: dpapad <dpapad@chromium.org>
Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#836319}

chrome/test/base/web_ui_browser_test.cc

@@ -396,13 +396,10 @@ class MockWebUIDataSource : public content::URLDataSource {
     return "text/html";
   }
 
-  // Append 'unsave-eval' to the default script-src CSP policy, since it is
-  // needed by some tests using chrome://dummyurl (because they depend on
-  // Mock4JS, see crbug.com/844820).
   std::string GetContentSecurityPolicy(
       const network::mojom::CSPDirectiveName directive) override {
     if (directive == network::mojom::CSPDirectiveName::ScriptSrc) {
-      return "script-src chrome://resources 'self' 'unsafe-eval';";
+      return "script-src chrome://resources 'self';";
     } else if (directive ==
                    network::mojom::CSPDirectiveName::RequireTrustedTypesFor ||
                directive == network::mojom::CSPDirectiveName::TrustedTypes) {