[chromedriver] Force DevTools screenshots by default.

chrome/test/chromedriver/capabilities.cc

 // 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.
 
 #include "chrome/test/chromedriver/capabilities.h"
 
 #include <map>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 594 matching lines @@
       page(InspectorDomainStatus::kDefaultEnabled),
       timeline(InspectorDomainStatus::kDefaultDisabled),
       trace_categories(),
       buffer_usage_reporting_interval(1000) {}
 
 PerfLoggingPrefs::~PerfLoggingPrefs() {}
 
 Capabilities::Capabilities()
     : android_use_running_app(false),
       detach(false),
-      force_devtools_screenshot(false),
+      force_devtools_screenshot(true),
       page_load_strategy(PageLoadStrategy::kNormal),
       network_emulation_enabled(false) {}
 
 Capabilities::~Capabilities() {}
 
 bool Capabilities::IsAndroid() const {
   return !android_package.empty();
 }
 
 bool Capabilities::IsRemoteBrowser() const {
@@ skipping 31 matching lines @@
   if (iter == logging_prefs.end() || iter->second == Log::kOff) {
     const base::DictionaryValue* chrome_options = NULL;
     if (desired_caps.GetDictionary("chromeOptions", &chrome_options) &&
         chrome_options->HasKey("perfLoggingPrefs")) {
       return Status(kUnknownError, "perfLoggingPrefs specified, "
                     "but performance logging was not enabled");
     }
   }
   return Status(kOk);
 }