Remove the backspace/shift+backspace navigating the page.

chrome/browser/ui/views/frame/browser_view.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/views/frame/browser_view.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 #include <memory>
@@ skipping 2424 matching lines @@
   if (command_id == IDC_BOOKMARK_PAGE)
     UMA_HISTOGRAM_ENUMERATION("Bookmarks.EntryPoint",
                               BOOKMARK_ENTRY_POINT_ACCELERATOR,
                               BOOKMARK_ENTRY_POINT_LIMIT);
 
 #if defined(OS_CHROMEOS)
   // Collect information about the relative popularity of various accelerators
   // on Chrome OS.
   switch (command_id) {
     case IDC_BACK:
-      if (key_code == ui::VKEY_BACK)
-        content::RecordAction(UserMetricsAction("Accel_Back_Backspace"));
-      else if (key_code == ui::VKEY_BROWSER_BACK)
+      if (key_code == ui::VKEY_BROWSER_BACK)
         content::RecordAction(UserMetricsAction("Accel_Back_F1"));
       else if (key_code == ui::VKEY_LEFT)
         content::RecordAction(UserMetricsAction("Accel_Back_Left"));
       break;
     case IDC_FORWARD:
-      if (key_code == ui::VKEY_BACK)
-        content::RecordAction(UserMetricsAction("Accel_Forward_Backspace"));
-      else if (key_code == ui::VKEY_BROWSER_FORWARD)
+      if (key_code == ui::VKEY_BROWSER_FORWARD)
         content::RecordAction(UserMetricsAction("Accel_Forward_F2"));
       else if (key_code == ui::VKEY_RIGHT)
         content::RecordAction(UserMetricsAction("Accel_Forward_Right"));
       break;
     case IDC_RELOAD:
     case IDC_RELOAD_BYPASSING_CACHE:
       if (key_code == ui::VKEY_R)
         content::RecordAction(UserMetricsAction("Accel_Reload_R"));
       else if (key_code == ui::VKEY_BROWSER_REFRESH)
         content::RecordAction(UserMetricsAction("Accel_Reload_F3"));
@@ skipping 180 matching lines @@
 }
 
 extensions::ActiveTabPermissionGranter*
 BrowserView::GetActiveTabPermissionGranter() {
   content::WebContents* web_contents = GetActiveWebContents();
   if (!web_contents)
     return nullptr;
   return extensions::TabHelper::FromWebContents(web_contents)
       ->active_tab_permission_granter();
 }