Get rid of TabContentsRegistrar and just let TabContentsObserver support dynamically changing the tab being observed.

Review URL: http://codereview.chromium.org/7058047

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@87860 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 18 insertions, 91 deletions

diff --git a/content/browser/tab_contents/tab_contents.h b/content/browser/tab_contents/tab_contents.h
index 164195f..8272696 100644
--- a/content/browser/tab_contents/tab_contents.h
+++ b/content/browser/tab_contents/tab_contents.h
@@ -485,7 +485,6 @@ class TabContents : public PageNavigator,
 
  protected:
   friend class TabContentsObserver;
-  friend class TabContentsObserverRegistrar;
 
   // Add and remove observers for page navigation notifications. Adding or
   // removing multiple times has no effect. The order in which notifications
diff --git a/content/browser/tab_contents/tab_contents_observer.cc b/content/browser/tab_contents/tab_contents_observer.cc
index 44a4d45..6ce40e8 100644
--- a/content/browser/tab_contents/tab_contents_observer.cc
+++ b/content/browser/tab_contents/tab_contents_observer.cc
@@ -82,9 +82,9 @@ void TabContentsObserver::DidOpenURL(const GURL& url,
                                      PageTransition::Type transition) {
 }
 
-TabContentsObserver::TabContentsObserver(TabContents* tab_contents) {
-  SetTabContents(tab_contents);
-  tab_contents_->AddObserver(this);
+TabContentsObserver::TabContentsObserver(TabContents* tab_contents)
+    : tab_contents_(NULL), routing_id_(MSG_ROUTING_NONE) {
+  Observe(tab_contents);
 }
 
 TabContentsObserver::TabContentsObserver()
@@ -96,6 +96,16 @@ TabContentsObserver::~TabContentsObserver() {
     tab_contents_->RemoveObserver(this);
 }
 
+void TabContentsObserver::Observe(TabContents* tab_contents) {
+  if (tab_contents_)
+    tab_contents_->RemoveObserver(this);
+  tab_contents_ = tab_contents;
+  if (tab_contents_) {
+    routing_id_ = tab_contents->render_view_host()->routing_id();
+    tab_contents_->AddObserver(this);
+  }
+}
+
 void TabContentsObserver::TabContentsDestroyed(TabContents* tab) {
 }
 
@@ -119,12 +129,6 @@ int TabContentsObserver::routing_id() const {
   return tab_contents_->render_view_host()->routing_id();
 }
 
-void TabContentsObserver::SetTabContents(TabContents* tab_contents) {
-  tab_contents_ = tab_contents;
-  if (tab_contents_)
-    routing_id_ = tab_contents->render_view_host()->routing_id();
-}
-
 void TabContentsObserver::TabContentsDestroyed() {
   // Do cleanup so that 'this' can safely be deleted from
   // TabContentsDestroyed.
diff --git a/content/browser/tab_contents/tab_contents_observer.h b/content/browser/tab_contents/tab_contents_observer.h
index f085062..d7c3d77 100644
--- a/content/browser/tab_contents/tab_contents_observer.h
+++ b/content/browser/tab_contents/tab_contents_observer.h
@@ -11,7 +11,6 @@
 #include "webkit/glue/window_open_disposition.h"
 
 class RenderViewHost;
-class TabContentsObserverRegistrar;
 struct ViewHostMsg_FrameNavigate_Params;
 
 // An observer API implemented by classes which are interested in various page
@@ -84,12 +83,15 @@ class TabContentsObserver : public IPC::Channel::Listener,
   explicit TabContentsObserver(TabContents* tab_contents);
 
   // Use this constructor when the object wants to observe a TabContents for
-  // part of its lifetime.  It can use a TabContentsObserverRegistrar member
-  // variable to start and stop observing.
+  // part of its lifetime.  It can then call Observe() to start and stop
+  // observing.
   TabContentsObserver();
 
   virtual ~TabContentsObserver();
 
+  // Start observing a different TabContents; used with the default constructor.
+  void Observe(TabContents* tab_contents);
+
   // Invoked when the TabContents is being destroyed. Gives subclasses a chance
   // to cleanup. At the time this is invoked |tab_contents()| returns NULL.
   // It is safe to delete 'this' from here.
@@ -104,11 +106,6 @@ class TabContentsObserver : public IPC::Channel::Listener,
   TabContents* tab_contents() const { return tab_contents_; }
   int routing_id() const;
 
-  friend class TabContentsObserverRegistrar;
-
-  // Called from TabContents in response to having |this| added as an observer.
-  void SetTabContents(TabContents* tab_contents);
-
  private:
   friend class TabContents;
 
diff --git a/content/browser/tab_contents/tab_contents_observer_registrar.cc b/content/browser/tab_contents/tab_contents_observer_registrar.cc
deleted file mode 100644
index 352525f..0000000
--- a/content/browser/tab_contents/tab_contents_observer_registrar.cc
+++ /dev/null
@@ -1,37 +0,0 @@
-// Copyright (c) 2011 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 "content/browser/tab_contents/tab_contents_observer_registrar.h"
-
-#include "content/browser/tab_contents/tab_contents.h"
-
-TabContentsObserverRegistrar::TabContentsObserverRegistrar(
-    TabContentsObserver* observer)
-    : observer_(observer), tab_(NULL) {
-}
-
-TabContentsObserverRegistrar::~TabContentsObserverRegistrar() {
-  if (tab_) {
-    tab_->RemoveObserver(observer_);
-    tab_->RemoveObserver(this);
-  }
-}
-
-void TabContentsObserverRegistrar::Observe(TabContents* tab) {
-  observer_->SetTabContents(tab);
-  SetTabContents(tab);
-  if (tab_) {
-    tab_->RemoveObserver(observer_);
-    tab_->RemoveObserver(this);
-  }
-  tab_ = tab;
-  if (tab_) {
-    tab_->AddObserver(observer_);
-    tab_->AddObserver(this);
-  }
-}
-
-void TabContentsObserverRegistrar::TabContentsDestroyed(TabContents* tab) {
-  Observe(NULL);
-}
diff --git a/content/browser/tab_contents/tab_contents_observer_registrar.h b/content/browser/tab_contents/tab_contents_observer_registrar.h
deleted file mode 100644
index fa488d9..0000000
--- a/content/browser/tab_contents/tab_contents_observer_registrar.h
+++ /dev/null
@@ -1,34 +0,0 @@
-// Copyright (c) 2011 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.
-
-#ifndef CONTENT_BROWSER_TAB_CONTENTS_TAB_CONTENTS_OBSERVER_REGISTRAR_H_
-#define CONTENT_BROWSER_TAB_CONTENTS_TAB_CONTENTS_OBSERVER_REGISTRAR_H_
-
-#include "content/browser/tab_contents/tab_contents_observer.h"
-
-// Use this as a member variable in a class that uses the empty constructor
-// version of this interface.  On destruction of TabContents being observed,
-// the registrar must either be destroyed or explicitly set to observe
-// another TabContents.
-class TabContentsObserverRegistrar : public TabContentsObserver {
- public:
-  explicit TabContentsObserverRegistrar(TabContentsObserver* observer);
-  virtual ~TabContentsObserverRegistrar();
-
-  // Call this to start observing a tab.  Passing in NULL resets it.
-  // This can only be used to watch one tab at a time.  If you call this and
-  // you're already observing another tab, the old tab won't be observed
-  // afterwards.
-  void Observe(TabContents* tab);
-
- private:
-  virtual void TabContentsDestroyed(TabContents* tab);
-
-  TabContentsObserver* observer_;
-  TabContents* tab_;
-
-  DISALLOW_COPY_AND_ASSIGN(TabContentsObserverRegistrar);
-};
-
-#endif  // CONTENT_BROWSER_TAB_CONTENTS_TAB_CONTENTS_OBSERVER_REGISTRAR_H_
diff --git a/content/content_browser.gypi b/content/content_browser.gypi
index 007cb34..f27de01 100644
--- a/content/content_browser.gypi
+++ b/content/content_browser.gypi
@@ -335,8 +335,6 @@
         'browser/tab_contents/tab_contents_delegate.h',
         'browser/tab_contents/tab_contents_observer.cc',
         'browser/tab_contents/tab_contents_observer.h',
-        'browser/tab_contents/tab_contents_observer_registrar.cc',
-        'browser/tab_contents/tab_contents_observer_registrar.h',
         'browser/tab_contents/tab_contents_view.cc',
         'browser/tab_contents/tab_contents_view.h',
         'browser/tab_contents/title_updated_details.h',