[Android] Fix new tab not to show 'about:blank' at the beginning

chrome/browser/ui/toolbar/toolbar_model_impl.cc

 // Copyright 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.
 
 #include "chrome/browser/ui/toolbar/toolbar_model_impl.h"
 
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 226 matching lines @@
 }
 
 GURL ToolbarModelImpl::GetURL() const {
   const NavigationController* navigation_controller = GetNavigationController();
   if (navigation_controller) {
     const NavigationEntry* entry = navigation_controller->GetVisibleEntry();
     if (entry)
       return ShouldDisplayURL() ? entry->GetVirtualURL() : GURL();
   }
 
-  return GURL(url::kAboutBlankURL);
+  return GURL();

[Maria, 2015/01/28 18:34:49]

It seems like if no original url was set, we will now get a different behaviour
in this case (empty string vs about:blank)

 }
 
 bool ToolbarModelImpl::WouldPerformSearchTermReplacement(
     bool ignore_editing) const {
   return !GetSearchTerms(ignore_editing).empty();
 }
 
 ToolbarModel::SecurityLevel ToolbarModelImpl::GetSecurityLevel(
     bool ignore_editing) const {
   // When editing, assume no security style.
@@ skipping 160 matching lines @@
   if (entry &&
       google_util::StartsWithCommandLineGoogleBaseURL(entry->GetVirtualURL()))
     return search_terms;
 
   // Otherwise, extract search terms for HTTPS pages that do not have a security
   // error.
   ToolbarModel::SecurityLevel security_level = GetSecurityLevel(ignore_editing);
   return ((security_level == NONE) || (security_level == SECURITY_ERROR)) ?
       base::string16() : search_terms;
 }