[Extensions][web_accessible_resources] Add wildcard test for clarity.

This should make it easier to for casual readers to see which wildcards
are allowed. Reference:
https://developer.chrome.com/docs/extensions/mv2/match_patterns/

Bug: 1133624
Change-Id: Ifd5b26e7b052f07c62dc0846cff4dfe922d52134
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2613512
Commit-Queue: Solomon Kinard <solomonkinard@chromium.org>
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#843313}

chrome/common/extensions/manifest_tests/extension_manifests_web_accessible_resources_unittest.cc

@@ -225,7 +225,8 @@ TEST_F(WebAccessibleResourcesManifestTest, WebAccessibleResourcesV3Invalid) {
 // Succeed if site requesting resource exists in matches.
 TEST_F(WebAccessibleResourcesManifestTest,
        WebAccessibleResourcesOriginRequestingResourceExistsInMatches) {
-  scoped_refptr<Extension> extension(LoadAndExpectSuccess(GetManifestData(R"([
+  scoped_refptr<Extension> extension(LoadAndExpectSuccess(GetManifestData(
+      R"([
         {
           "resources": ["test"],
           "matches": ["https://allowed.example/*"]
@@ -301,3 +302,36 @@ TEST_F(WebAccessibleResourcesManifestTest,
   EXPECT_FALSE(WebAccessibleResourcesInfo::IsResourceWebAccessible(
       extension1.get(), "test", initiator_origin));
 }
+
+// Tests wildcards
+TEST_F(WebAccessibleResourcesManifestTest, WebAccessibleResourcesWildcard) {
+  struct {
+    const char* title;
+    const char* web_accessible_resources;
+  } test_cases[] = {
+      {"Succeed if text based wildcard is used.",
+       R"([
+            {
+              "resources": ["test"],
+              "matches": ["<all_urls>"]
+            }
+       ])"},
+      {"Succeed if asterisk based wildcard is used.",
+       R"([
+            {
+              "resources": ["test"],
+              "matches": ["*://*/*"]
+            }
+       ])"},
+  };
+  for (const auto& test_case : test_cases) {
+    SCOPED_TRACE(base::StringPrintf("Error: '%s'", test_case.title));
+    scoped_refptr<Extension> extension(LoadAndExpectSuccess(
+        GetManifestData(test_case.web_accessible_resources)));
+    EXPECT_TRUE(
+        WebAccessibleResourcesInfo::HasWebAccessibleResources(extension.get()));
+    EXPECT_TRUE(WebAccessibleResourcesInfo::IsResourceWebAccessible(
+        extension.get(), "test",
+        url::Origin::Create(GURL("https://allowed.example"))));
+  }
+}