athena: Add the concept of Activity and related managers.

athena/main/web_activity.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 "athena/main/web_activity.h"
+
+#include "athena/activity/public/activity_manager.h"
+#include "base/strings/utf_string_conversions.h"
+#include "content/public/browser/web_contents.h"
+
+WebActivity::WebActivity(content::WebContents* contents)
+    : content::WebContentsObserver(contents) {
+}
+
+WebActivity::~WebActivity() {
+  athena::ActivityManager::Get()->RemoveActivity(this);
+}
+
+athena::ActivityViewModel* WebActivity::GetActivityViewModel() {
+  return this;
+}
+
+SkColor WebActivity::GetRepresentativeColor() {
+  // TODO(sad): Compute the color from the favicon.
+  return SK_ColorGRAY;
+}
+
+std::string WebActivity::GetTitle() {
+  return base::UTF16ToUTF8(web_contents()->GetTitle());
+}
+
+aura::Window* WebActivity::GetNativeWindow() {
+  return web_contents()->GetNativeView();
+}
+
+void WebActivity::TitleWasSet(content::NavigationEntry* entry,
+                              bool explicit_set) {
+  athena::ActivityManager::Get()->UpdateActivity(this);
+}
+
+void WebActivity::DidUpdateFaviconURL(
+    const std::vector<content::FaviconURL>& candidates) {
+  athena::ActivityManager::Get()->UpdateActivity(this);
+}