Forbid content translate driver from initiating translation for page forward/back.

components/translate/content/browser/content_translate_driver.cc

 // Copyright 2014 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 "components/translate/content/browser/content_translate_driver.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 171 matching lines @@
     return;
   }
 
   // If not a reload, return.
   if (!ui::PageTransitionCoreTypeIs(entry->GetTransitionType(),
                                     ui::PAGE_TRANSITION_RELOAD) &&
       load_details.type != content::NAVIGATION_TYPE_SAME_PAGE) {
     return;
   }
 
+  if (entry->GetTransitionType() & ui::PAGE_TRANSITION_FORWARD_BACK) {
+    // Workaround for http://crbug.com/653051: back navigation sometimes have
+    // the reload core type. Once http://crbug.com/669008 got resolved, we
+    // could revisit here for a thorough solution.
+    return;
+  }
+
   if (!translate_manager_->GetLanguageState().page_needs_translation())
     return;
 
   // Note that we delay it as the ordering of the processing of this callback
   // by WebContentsObservers is undefined and might result in the current
   // infobars being removed. Since the translation initiation process might add
   // an infobar, it must be done after that.
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE,
       base::Bind(&ContentTranslateDriver::InitiateTranslation,
@@ skipping 48 matching lines @@
   if (cancelled)
     return;
 
   translate_manager_->PageTranslated(
       original_lang, translated_lang, error_type);
   for (auto& observer : observer_list_)
     observer.OnPageTranslated(original_lang, translated_lang, error_type);
 }
 
 }  // namespace translate