[Merge] Make mouse buttons 8 - 11 navigate forward and back in history

chrome/browser/ui/views/frame/browser_command_handler_linux.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 "chrome/browser/ui/views/frame/browser_command_handler_linux.h"
+
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/browser/ui/views/frame/browser_view.h"
+#include "content/public/browser/navigation_controller.h"
+#include "content/public/browser/web_contents.h"
+#include "ui/aura/window.h"
+#include "ui/events/event.h"
+
+BrowserCommandHandlerLinux::BrowserCommandHandlerLinux(
+    BrowserView* browser_view)
+    : browser_view_(browser_view) {
+  aura::Window* window = browser_view_->frame()->GetNativeWindow();
+  DCHECK(window);
+  if (window)
+    window->AddPreTargetHandler(this);
+}
+
+BrowserCommandHandlerLinux::~BrowserCommandHandlerLinux() {
+  aura::Window* window = browser_view_->frame()->GetNativeWindow();
+  if (window)
+    window->RemovePreTargetHandler(this);
+}
+
+void BrowserCommandHandlerLinux::OnMouseEvent(ui::MouseEvent* event) {
+  // Handle standard Linux mouse buttons for going back and forward.
+  if (event->type() != ui::ET_MOUSE_PRESSED)
+    return;
+
+  bool back_button_pressed =
+      (event->changed_button_flags() == ui::EF_BACK_MOUSE_BUTTON);
+  bool forward_button_pressed =
+      (event->changed_button_flags() == ui::EF_FORWARD_MOUSE_BUTTON);
+  if (!back_button_pressed && !forward_button_pressed)
+    return;
+
+  content::WebContents* contents =
+      browser_view_->browser()->tab_strip_model()->GetActiveWebContents();
+  if (!contents)
+    return;
+  content::NavigationController& controller = contents->GetController();
+  if (back_button_pressed && controller.CanGoBack())
+    controller.GoBack();
+  else if (forward_button_pressed && controller.CanGoForward())
+    controller.GoForward();
+  // Always consume the event, whether a navigation was successful or not.
+  event->SetHandled();
+}