ChromeOS Web UI Tests: make WebUIBrowserTest error message more readable.

chrome/test/base/web_ui_browser_test.cc

Index: chrome/test/base/web_ui_browser_test.cc
diff --git a/chrome/test/base/web_ui_browser_test.cc b/chrome/test/base/web_ui_browser_test.cc
index 4a55e86fc2e041d9b37aca86663e4c6dc6f2a426..5dd111115f0265efbb10e82bce7cccf93195bc04 100644
--- a/chrome/test/base/web_ui_browser_test.cc
+++ b/chrome/test/base/web_ui_browser_test.cc
@@ -459,7 +459,12 @@ bool WebUIBrowserTest::RunJavascriptUsingHandler(
     test_handler_->RunJavaScript(content);
 
   if (error_messages_.Get().size() > 0) {
-    LOG(ERROR) << "Encountered javascript console error(s)";
+    LOG(ERROR) << "CONDITION FAILURE: encountered javascript console error(s):";
+    for (const auto& msg : error_messages_.Get()) {
+      LOG(ERROR) << "JS ERROR: '" << msg << "'";

[michaelpg, 2016/07/29 22:38:29]

Do you not normally see console errors when your tests fail? I'm seeing
duplicate errors now because they're logged first during the test, and then
again at the end here. That's annoying IMO -- is this WAI?

+    }
+    LOG(ERROR) << "JS call assumed failed, because JS console error(s) found.";
+
     result = false;
     error_messages_.Get().clear();
   }