Enable extensions error button test that was failing on stable.

chrome/browser/extensions/error_console/error_console.cc

 // Copyright 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.
 
 #include "chrome/browser/extensions/error_console/error_console.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 151 matching lines @@
   DCHECK(thread_checker_.CalledOnValidThread());
   observers_.AddObserver(observer);
 }
 
 void ErrorConsole::RemoveObserver(Observer* observer) {
   DCHECK(thread_checker_.CalledOnValidThread());
   observers_.RemoveObserver(observer);
 }
 
 bool ErrorConsole::IsEnabledForChromeExtensionsPage() const {
+  FeatureSwitch* error_console = FeatureSwitch::error_console();

[Devlin, 2015/05/07 23:04:14]

I think this boolean result is right, but it's hard to read. :)

Let's do:
if (error_console->GetOverrideValue() == FeatureSwitch::OVERRIDE_DISABLED)
  return false;  // Explicitly disabled for testing.
if (!profile_->GetPrefs()->GetBoolean(prefs::kExtensionsUIDeveloperMode)
  return false;  // Only enabled in developer mode.
if (GetCurrentChannel() > chrome::VersionInfo::CHANNEL_DEV &&
    !error_console->IsEnabled())
  return false;  // Restricted to dev channel or opt-in.

return true;

It's a few more lines, but I think the readability is worthwhile.

[Dan Beam, 2015/05/07 23:08:44]

+10

   return profile_->GetPrefs()->GetBoolean(prefs::kExtensionsUIDeveloperMode) &&
-         (FeatureSwitch::error_console()->IsEnabled() ||
-          GetCurrentChannel() <= chrome::VersionInfo::CHANNEL_DEV);
+         (error_console->IsEnabled() ||
+          GetCurrentChannel() <= chrome::VersionInfo::CHANNEL_DEV) &&
+         error_console->GetOverrideValue() != FeatureSwitch::OVERRIDE_DISABLED;
 }
 
 bool ErrorConsole::IsEnabledForAppsDeveloperTools() const {
   return ExtensionRegistry::Get(profile_)->enabled_extensions()
       .Contains(kAppsDeveloperToolsExtensionId);
 }
 
 void ErrorConsole::CheckEnabled() {
   bool should_be_enabled = IsEnabledForChromeExtensionsPage() ||
                            IsEnabledForAppsDeveloperTools();
@@ skipping 102 matching lines @@
       ExtensionRegistry::Get(profile_)->GetExtensionById(
           extension_id, ExtensionRegistry::EVERYTHING);
   if (extension && extension->location() == Manifest::UNPACKED)
     return (1 << ExtensionError::NUM_ERROR_TYPES) - 1;
 
   // Otherwise, use the default mask.
   return default_mask_;
 }
 
 }  // namespace extensions