[chromedriver] Add an error autoreporting feature that automatically raises errors from browser logs

chrome/test/chromedriver/logging.h

 // Copyright (c) 2013 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.
 
 #ifndef CHROME_TEST_CHROMEDRIVER_LOGGING_H_
 #define CHROME_TEST_CHROMEDRIVER_LOGGING_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 21 matching lines @@
   // Creates a WebDriverLog with the given type and minimum level.
   WebDriverLog(const std::string& type, Level min_level);
   virtual ~WebDriverLog();
 
   // Returns entries accumulated so far, as a ListValue ready for serialization
   // into the wire protocol response to the "/log" command.
   // The caller assumes ownership of the ListValue, and the WebDriverLog
   // creates and owns a new empty ListValue for further accumulation.
   scoped_ptr<base::ListValue> GetAndClearEntries();
 
+  // Finds the first error message in the log and returns it. If none exist,

[chrisgao (Use stgao instead), 2014/01/09 22:11:55]

nit: exist -> exists ?

[samuong, 2014/01/16 00:29:28]

I think it's "if none exist" or "if nothing exists", but not "if none exists".
Frank, let me know if I'm wrong.

+  // returns an empty string. Does not clear entries.
+  std::string GetFirstErrorMessage() const;

[chrisgao (Use stgao instead), 2014/01/09 22:11:55]

What's the consideration behind only returning the first error message, not all
available error messages?

[samuong, 2014/01/16 00:29:28]

The first error message gets returned to the client, and gets used as the
exception message. I don't think it's necessary to return all error messages,
but if the client is interested it can always call the GET_LOG command.

+
   // Translates a Log entry level into a WebDriver level and stores the entry.
   virtual void AddEntryTimestamped(const base::Time& timestamp,
                                    Level level,
                                    const std::string& source,
                                    const std::string& message) OVERRIDE;
 
   const std::string& type() const;
   void set_min_level(Level min_level);
   Level min_level() const;
 
  private:
   const std::string type_;  // WebDriver log type.
   Level min_level_;  // Minimum level of entries to store.
   scoped_ptr<base::ListValue> entries_;  // Accumulated entries.
 
   DISALLOW_COPY_AND_ASSIGN(WebDriverLog);
 };
 
 // Initializes logging system for ChromeDriver. Returns true on success.
 bool InitLogging();
 
 // Creates Log's and DevToolsEventListener's based on logging preferences.
 Status CreateLogs(const Capabilities& capabilities,
                   ScopedVector<WebDriverLog>* out_logs,
                   ScopedVector<DevToolsEventListener>* out_listeners);
 
 #endif  // CHROME_TEST_CHROMEDRIVER_LOGGING_H_