Reduce calling count of UpdateAppState()

chrome/browser/ui/ash/launcher/browser_status_monitor.cc

Index: chrome/browser/ui/ash/launcher/browser_status_monitor.cc
diff --git a/chrome/browser/ui/ash/launcher/browser_status_monitor.cc b/chrome/browser/ui/ash/launcher/browser_status_monitor.cc
index c9965ed1b419acd26631e71fa2b4b000c4a1f1a7..514fb1073175509e590e881ac058df104d0a0316 100644
--- a/chrome/browser/ui/ash/launcher/browser_status_monitor.cc
+++ b/chrome/browser/ui/ash/launcher/browser_status_monitor.cc
@@ -6,6 +6,7 @@
 
 #include "ash/shell.h"
 #include "ash/wm/window_util.h"
+#include "base/stl_util.h"
 #include "chrome/browser/ui/ash/launcher/browser_shortcut_launcher_item_controller.h"
 #include "chrome/browser/ui/ash/launcher/chrome_launcher_controller.h"
 #include "chrome/browser/ui/browser.h"
@@ -15,12 +16,35 @@
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/web_applications/web_app.h"
 #include "content/public/browser/web_contents.h"
-#include "content/public/browser/web_contents_view.h"
 #include "ui/aura/client/activation_client.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
 #include "ui/gfx/screen.h"
 
+BrowserStatusMonitor::LocalWebContentsObserver::LocalWebContentsObserver(
+    content::WebContents* contents,
+    BrowserStatusMonitor* monitor)
+    : content::WebContentsObserver(contents),
+      monitor_(monitor) {
+}
+
+BrowserStatusMonitor::LocalWebContentsObserver::~LocalWebContentsObserver() {
+}
+
+void BrowserStatusMonitor::LocalWebContentsObserver::DidNavigateMainFrame(
+    const content::LoadCommittedDetails& details,
+    const content::FrameNavigateParams& params) {
+  Browser* browser = chrome::FindBrowserWithWebContents(web_contents());
+  ChromeLauncherController::AppState state =
+      ChromeLauncherController::APP_STATE_ACTIVE;
+  if (browser->window()->IsActive() &&
+      browser->tab_strip_model()->GetActiveWebContents() == web_contents())
+    state = ChromeLauncherController::APP_STATE_WINDOW_ACTIVE;
+
+  monitor_->UpdateAppItemState(web_contents(), state);
+  monitor_->UpdateBrowserItemState();
+}
+
 BrowserStatusMonitor::BrowserStatusMonitor(
     ChromeLauncherController* launcher_controller)
     : launcher_controller_(launcher_controller),
@@ -62,21 +86,54 @@ BrowserStatusMonitor::~BrowserStatusMonitor() {
        i != browser_list->end(); ++i) {
     OnBrowserRemoved(*i);
   }
+
+  STLDeleteContainerPairSecondPointers(webcontents_to_observer_map_.begin(),
+                                       webcontents_to_observer_map_.end());
+}
+
+void BrowserStatusMonitor::UpdateAppItemState(
+    content::WebContents* contents,
+    ChromeLauncherController::AppState app_state) {
+  DCHECK(contents);
+  launcher_controller_->UpdateAppState(contents, app_state);
+}
+
+void BrowserStatusMonitor::UpdateBrowserItemState() {
+  launcher_controller_->GetBrowserShortcutLauncherItemController()->
+      UpdateBrowserItemState();
 }
 
 void BrowserStatusMonitor::OnWindowActivated(aura::Window* gained_active,
                                              aura::Window* lost_active) {
-  Browser* browser = chrome::FindBrowserWithWindow(lost_active);
-  if (browser) {
-    UpdateAppAndBrowserState(
-        browser->tab_strip_model()->GetActiveWebContents());
+  Browser* browser = NULL;
+  content::WebContents* contents_from_gained = NULL;
+  content::WebContents* contents_from_lost = NULL;
+  // Update active webcontents's app item state of |lost_active|, if existed.
+  if (lost_active) {
+    browser = chrome::FindBrowserWithWindow(lost_active);
+    if (browser)
+      contents_from_lost = browser->tab_strip_model()->GetActiveWebContents();
+    if (contents_from_lost) {
+      UpdateAppItemState(
+          contents_from_lost,
+          ChromeLauncherController::APP_STATE_INACTIVE);
+    }
   }
 
-  browser = chrome::FindBrowserWithWindow(gained_active);
-  if (browser) {
-    UpdateAppAndBrowserState(
-        browser->tab_strip_model()->GetActiveWebContents());
+  // Update active webcontents's app item state of |gained_active|, if existed.
+  if (gained_active) {
+    browser = chrome::FindBrowserWithWindow(gained_active);
+    if (browser)
+      contents_from_gained = browser->tab_strip_model()->GetActiveWebContents();
+    if (contents_from_gained) {
+      UpdateAppItemState(
+          contents_from_gained,
+          ChromeLauncherController::APP_STATE_WINDOW_ACTIVE);
+    }
   }
+
+  if (contents_from_lost || contents_from_gained)
+    UpdateBrowserItemState();
 }
 
 void BrowserStatusMonitor::OnWindowDestroyed(aura::Window* window) {
@@ -145,77 +202,85 @@ void BrowserStatusMonitor::ActiveTabChanged(content::WebContents* old_contents,
                                             int index,
                                             int reason) {
   Browser* browser = NULL;
-  if (old_contents)
-    browser = chrome::FindBrowserWithWebContents(old_contents);
+  // Use |new_contents|. |old_contents| could be NULL.
+  DCHECK(new_contents);
+  browser = chrome::FindBrowserWithWebContents(new_contents);
 
   if (browser && browser->host_desktop_type() != chrome::HOST_DESKTOP_TYPE_ASH)
     return;
 
+  ChromeLauncherController::AppState state =
+      ChromeLauncherController::APP_STATE_INACTIVE;
+
   // Update immediately on a tab change.
-  if (browser &&
+  if (old_contents &&
       (TabStripModel::kNoTab !=
-           browser->tab_strip_model()->GetIndexOfWebContents(old_contents))) {
-    launcher_controller_->UpdateAppState(
-        old_contents,
-        ChromeLauncherController::APP_STATE_INACTIVE);
+           browser->tab_strip_model()->GetIndexOfWebContents(old_contents)))
+    UpdateAppItemState(old_contents, state);
+
+  if (new_contents) {
+    state = browser->window()->IsActive() ?
+        ChromeLauncherController::APP_STATE_WINDOW_ACTIVE :
+        ChromeLauncherController::APP_STATE_ACTIVE;
+    UpdateAppItemState(new_contents, state);
+    UpdateBrowserItemState();
   }
+}
 
-  UpdateAppAndBrowserState(new_contents);
+void BrowserStatusMonitor::TabReplacedAt(TabStripModel* tab_strip_model,
+                                         content::WebContents* old_contents,
+                                         content::WebContents* new_contents,
+                                         int index) {
+  DCHECK(old_contents && new_contents);
+  Browser* browser = chrome::FindBrowserWithWebContents(new_contents);
+
+  if (browser && browser->host_desktop_type() != chrome::HOST_DESKTOP_TYPE_ASH)
+    return;
+
+  UpdateAppItemState(old_contents,
+                     ChromeLauncherController::APP_STATE_REMOVED);
+  RemoveWebContentsObserver(old_contents);
+
+  ChromeLauncherController::AppState state =
+      ChromeLauncherController::APP_STATE_ACTIVE;
+  if (browser->window()->IsActive() &&
+      (tab_strip_model->GetActiveWebContents() == new_contents))
+    state = ChromeLauncherController::APP_STATE_WINDOW_ACTIVE;
+  UpdateAppItemState(new_contents, state);
+  AddWebContentsObserver(new_contents);
 }
 
 void BrowserStatusMonitor::TabInsertedAt(content::WebContents* contents,
                                          int index,
                                          bool foreground) {
-  UpdateAppAndBrowserState(contents);
+  // An inserted tab is not active - ActiveTabChanged() will be called to
+  // activate. We initialize therefore with |APP_STATE_INACTIVE|.
+  UpdateAppItemState(contents,
+                     ChromeLauncherController::APP_STATE_INACTIVE);
+  AddWebContentsObserver(contents);
 }
 
-void BrowserStatusMonitor::TabDetachedAt(content::WebContents* contents,
-                                         int index) {
-  launcher_controller_->UpdateAppState(
-      contents, ChromeLauncherController::APP_STATE_REMOVED);
-  UpdateBrowserItemState();
-}
-
-void BrowserStatusMonitor::TabChangedAt(
-    content::WebContents* contents,
-    int index,
-    TabStripModelObserver::TabChangeType change_type) {
-  UpdateAppAndBrowserState(contents);
+void BrowserStatusMonitor::TabClosingAt(TabStripModel* tab_strip_mode,
+                                        content::WebContents* contents,
+                                        int index) {
+  UpdateAppItemState(contents,
+                     ChromeLauncherController::APP_STATE_REMOVED);
+  RemoveWebContentsObserver(contents);
 }
 
-void BrowserStatusMonitor::TabReplacedAt(TabStripModel* tab_strip_model,
-                                         content::WebContents* old_contents,
-                                         content::WebContents* new_contents,
-                                         int index) {
-  launcher_controller_->UpdateAppState(
-      old_contents,
-      ChromeLauncherController::APP_STATE_REMOVED);
-  UpdateAppAndBrowserState(new_contents);
-}
-
-void BrowserStatusMonitor::UpdateAppAndBrowserState(
+void BrowserStatusMonitor::AddWebContentsObserver(
     content::WebContents* contents) {
-  if (contents) {
-    ChromeLauncherController::AppState app_state =
-        ChromeLauncherController::APP_STATE_INACTIVE;
-
-    Browser* browser = chrome::FindBrowserWithWebContents(contents);
-    DCHECK(browser);
-    if (browser->host_desktop_type() != chrome::HOST_DESKTOP_TYPE_ASH)
-      return;
-    if (browser->tab_strip_model()->GetActiveWebContents() == contents) {
-      if (browser->window()->IsActive())
-        app_state = ChromeLauncherController::APP_STATE_WINDOW_ACTIVE;
-      else
-        app_state = ChromeLauncherController::APP_STATE_ACTIVE;
-    }
-
-    launcher_controller_->UpdateAppState(contents, app_state);
+  if (webcontents_to_observer_map_.find(contents) ==
+          webcontents_to_observer_map_.end()) {
+    webcontents_to_observer_map_[contents] =
+        new LocalWebContentsObserver(contents, this);
   }
-  UpdateBrowserItemState();
 }
 
-void BrowserStatusMonitor::UpdateBrowserItemState() {
-  launcher_controller_->GetBrowserShortcutLauncherItemController()->
-      UpdateBrowserItemState();
+void BrowserStatusMonitor::RemoveWebContentsObserver(
+    content::WebContents* contents) {
+  DCHECK(webcontents_to_observer_map_.find(contents) !=
+      webcontents_to_observer_map_.end());
+  delete webcontents_to_observer_map_[contents];
+  webcontents_to_observer_map_.erase(contents);
 }