Properly check the visibility of elements in browsertests

chrome/browser/safe_browsing/safe_browsing_blocking_page_test.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // This test creates a fake safebrowsing service, where we can inject known-
 // threat urls.  It then uses a real browser to go to these urls, and sends
 // "goback" or "proceed" commands and verifies they work.
 
 #include <algorithm>
 
@@ skipping 544 matching lines @@
     if (!interstitial)
       return false;
     return content::WaitForRenderFrameReady(interstitial->GetMainFrame());
   }
 
   Visibility GetVisibility(const std::string& node_id) {
     content::RenderFrameHost* rfh = GetRenderFrameHost();
     if (!rfh)
       return VISIBILITY_ERROR;
 
-    std::unique_ptr<base::Value> value = content::ExecuteScriptAndGetValue(
-        rfh, "var node = document.getElementById('" + node_id +
-                 "');\n"
-                 "if (node)\n"
-                 "   node.offsetWidth > 0 && node.offsetHeight > 0;"
-                 "else\n"
-                 "  'node not found';\n");
+    // clang-format off
+    std::string jsFindVisibility = R"(
+      (function isNodeVisible(node) {
+        if (!node) return 'node not found';
+        if (node.offsetWidth === 0 || node.offsetHeight === 0) return false;
+        // Don't check opacity, since the css transition may actually leave

[Jialiu Lin, 2017/04/28 18:14:08]

nit: "Don't" -> "Do not"

codereview.chromium.org seems confused on how to properly display syntax colorof
this part beause of this '

[Nate Fischer, 2017/04/28 18:26:25]

Done.

+        // opacity at 0 after it's been unhidden
+        if (node.classList.contains('hidden')) return false;
+        // Otherwise, we must check all parent nodes
+        var parentVisibility = isNodeVisible(node.parentElement);
+        if (parentVisibility === 'node not found') {
+          return true; // none of the parents are set invisible
+        }
+        return parentVisibility;
+      }(document.getElementById(')" + node_id + R"(')));)";
+    // clang-format on
+
+    std::unique_ptr<base::Value> value =
+        content::ExecuteScriptAndGetValue(rfh, jsFindVisibility);
+
     if (!value.get())
       return VISIBILITY_ERROR;
 
     bool result = false;
     if (!value->GetAsBoolean(&result))
       return VISIBILITY_ERROR;
 
     return result ? VISIBLE : HIDDEN;
   }
 
@@ skipping 891 matching lines @@
 
 INSTANTIATE_TEST_CASE_P(
     SafeBrowsingBlockingPageIDNTestWithThreatType,
     SafeBrowsingBlockingPageIDNTest,
     testing::Combine(testing::Values(false, true),
                      testing::Values(SB_THREAT_TYPE_URL_MALWARE,
                                      SB_THREAT_TYPE_URL_PHISHING,
                                      SB_THREAT_TYPE_URL_UNWANTED)));
 
 }  // namespace safe_browsing