Moves TabStripModelObserver/Delegate into their own headers.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/3425009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@59733 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 345 insertions, 313 deletions

diff --git a/chrome/browser/tabs/pinned_tab_codec_unittest.cc b/chrome/browser/tabs/pinned_tab_codec_unittest.cc
index a94934c..6737c01 100644
--- a/chrome/browser/tabs/pinned_tab_codec_unittest.cc
+++ b/chrome/browser/tabs/pinned_tab_codec_unittest.cc
@@ -6,6 +6,7 @@
 #include <vector>
 
 #include "chrome/browser/tabs/pinned_tab_codec.h"
+#include "chrome/browser/tabs/tab_strip_model.h"
 #include "chrome/test/browser_with_test_window_test.h"
 #include "chrome/test/testing_profile.h"
 #include "testing/gtest/include/gtest/gtest.h"
diff --git a/chrome/browser/tabs/tab_strip_model.cc b/chrome/browser/tabs/tab_strip_model.cc
index 4f6cfde..14df8d1 100644
--- a/chrome/browser/tabs/tab_strip_model.cc
+++ b/chrome/browser/tabs/tab_strip_model.cc
@@ -18,6 +18,7 @@
 #include "chrome/browser/profile.h"
 #include "chrome/browser/renderer_host/render_process_host.h"
 #include "chrome/browser/sessions/tab_restore_service.h"
+#include "chrome/browser/tabs/tab_strip_model_delegate.h"
 #include "chrome/browser/tabs/tab_strip_model_order_controller.h"
 #include "chrome/browser/tab_contents/navigation_controller.h"
 #include "chrome/browser/tab_contents/tab_contents.h"
@@ -46,66 +47,6 @@ bool ShouldForgetOpenersForTransition(PageTransition::Type transition) {
 }  // namespace
 
 ///////////////////////////////////////////////////////////////////////////////
-// TabStripModelObserver, public:
-
-void TabStripModelObserver::TabInsertedAt(TabContents* contents,
-                                          int index,
-                                          bool foreground) {
-}
-
-void TabStripModelObserver::TabClosingAt(TabContents* contents, int index) {
-}
-
-void TabStripModelObserver::TabDetachedAt(TabContents* contents, int index) {
-}
-
-void TabStripModelObserver::TabDeselectedAt(TabContents* contents, int index) {
-}
-
-void TabStripModelObserver::TabSelectedAt(TabContents* old_contents,
-                                          TabContents* new_contents,
-                                          int index,
-                                          bool user_gesture) {
-}
-
-void TabStripModelObserver::TabMoved(TabContents* contents,
-                                     int from_index,
-                                     int to_index) {
-}
-
-void TabStripModelObserver::TabChangedAt(TabContents* contents, int index,
-                                         TabChangeType change_type) {
-}
-
-void TabStripModelObserver::TabReplacedAt(TabContents* old_contents,
-                                          TabContents* new_contents,
-                                          int index) {
-}
-
-void TabStripModelObserver::TabReplacedAt(TabContents* old_contents,
-                                          TabContents* new_contents,
-                                          int index,
-                                          TabReplaceType type) {
-  TabReplacedAt(old_contents, new_contents, index);
-}
-
-void TabStripModelObserver::TabPinnedStateChanged(TabContents* contents,
-                                                  int index) {
-}
-
-void TabStripModelObserver::TabMiniStateChanged(TabContents* contents,
-                                                int index) {
-}
-
-void TabStripModelObserver::TabBlockedStateChanged(TabContents* contents,
-                                                   int index) {
-}
-
-void TabStripModelObserver::TabStripEmpty() {}
-
-void TabStripModelObserver::TabStripModelDeleted() {}
-
-///////////////////////////////////////////////////////////////////////////////
 // TabStripModelDelegate, public:
 
 bool TabStripModelDelegate::CanCloseTab() const {
diff --git a/chrome/browser/tabs/tab_strip_model.h b/chrome/browser/tabs/tab_strip_model.h
index 5143207..003f3d6 100644
--- a/chrome/browser/tabs/tab_strip_model.h
+++ b/chrome/browser/tabs/tab_strip_model.h
@@ -9,267 +9,16 @@
 #include <vector>
 
 #include "base/observer_list.h"
+#include "chrome/browser/tabs/tab_strip_model_observer.h"
 #include "chrome/common/notification_observer.h"
 #include "chrome/common/notification_registrar.h"
 #include "chrome/common/page_transition_types.h"
 
-namespace gfx {
-class Rect;
-}
-class Browser;
-class DockInfo;
-class GURL;
 class NavigationController;
 class Profile;
-class SiteInstance;
 class TabContents;
+class TabStripModelDelegate;
 class TabStripModelOrderController;
-class TabStripModel;
-
-////////////////////////////////////////////////////////////////////////////////
-//
-// TabStripModelObserver
-//
-//  Objects implement this interface when they wish to be notified of changes
-//  to the TabStripModel.
-//
-//  Two major implementers are the TabStrip, which uses notifications sent
-//  via this interface to update the presentation of the strip, and the Browser
-//  object, which updates bookkeeping and shows/hides individual TabContentses.
-//
-//  Register your TabStripModelObserver with the TabStripModel using its
-//  Add/RemoveObserver methods.
-//
-////////////////////////////////////////////////////////////////////////////////
-class TabStripModelObserver {
- public:
-  // Enumeration of the possible values supplied to TabChangedAt.
-  enum TabChangeType {
-    // Only the loading state changed.
-    LOADING_ONLY,
-
-    // Only the title changed and page isn't loading.
-    TITLE_NOT_LOADING,
-
-    // Change not characterized by LOADING_ONLY or TITLE_NOT_LOADING.
-    ALL
-  };
-
-  // Enum used by ReplaceTabContentsAt.
-  // TODO(sky): TabReplaceType should be declared outside the scope of
-  // the observer. I need to put all the enums in a namespace and cleanup this
-  // file.
-  enum TabReplaceType {
-    // The replace is the result of the tab being made phantom.
-    REPLACE_MADE_PHANTOM,
-
-    // The replace is the result of the match preview being committed.
-    REPLACE_MATCH_PREVIEW
-  };
-
-  // A new TabContents was inserted into the TabStripModel at the specified
-  // index. |foreground| is whether or not it was opened in the foreground
-  // (selected).
-  virtual void TabInsertedAt(TabContents* contents,
-                             int index,
-                             bool foreground);
-
-  // The specified TabContents at |index| is being closed (and eventually
-  // destroyed).
-  virtual void TabClosingAt(TabContents* contents, int index);
-
-  // The specified TabContents at |index| is being detached, perhaps to be
-  // inserted in another TabStripModel. The implementer should take whatever
-  // action is necessary to deal with the TabContents no longer being present.
-  virtual void TabDetachedAt(TabContents* contents, int index);
-
-  // The selected TabContents is about to change from |old_contents| at |index|.
-  // This gives observers a chance to prepare for an impending switch before it
-  // happens.
-  virtual void TabDeselectedAt(TabContents* contents, int index);
-
-  // The selected TabContents changed from |old_contents| to |new_contents| at
-  // |index|. |user_gesture| specifies whether or not this was done by a user
-  // input event (e.g. clicking on a tab, keystroke) or as a side-effect of
-  // some other function.
-  virtual void TabSelectedAt(TabContents* old_contents,
-                             TabContents* new_contents,
-                             int index,
-                             bool user_gesture);
-
-  // The specified TabContents at |from_index| was moved to |to_index|.
-  virtual void TabMoved(TabContents* contents,
-                        int from_index,
-                        int to_index);
-
-  // The specified TabContents at |index| changed in some way. |contents| may
-  // be an entirely different object and the old value is no longer available
-  // by the time this message is delivered.
-  //
-  // See TabChangeType for a description of |change_type|.
-  virtual void TabChangedAt(TabContents* contents, int index,
-                            TabChangeType change_type);
-
-  // The tab contents was replaced at the specified index. This is invoked when
-  // a tab becomes phantom. See description of phantom tabs in class description
-  // of TabStripModel for details.
-  // TODO(sky): nuke this in favor of the 4 arg variant.
-  virtual void TabReplacedAt(TabContents* old_contents,
-                             TabContents* new_contents,
-                             int index);
-
-  // The tab contents was replaced at the specified index. |type| describes
-  // the type of replace.
-  // This invokes TabReplacedAt with three args.
-  virtual void TabReplacedAt(TabContents* old_contents,
-                             TabContents* new_contents,
-                             int index,
-                             TabReplaceType type);
-
-  // Invoked when the pinned state of a tab changes. This is not invoked if the
-  // tab ends up moving as a result of the mini state changing.
-  // See note in TabMiniStateChanged as to how this relates to
-  // TabMiniStateChanged.
-  virtual void TabPinnedStateChanged(TabContents* contents, int index);
-
-  // Invoked if the mini state of a tab changes.  This is not invoked if the
-  // tab ends up moving as a result of the mini state changing.
-  // NOTE: this is sent when the pinned state of a non-app tab changes and is
-  // sent in addition to TabPinnedStateChanged. UI code typically need not care
-  // about TabPinnedStateChanged, but instead this.
-  virtual void TabMiniStateChanged(TabContents* contents, int index);
-
-  // Invoked when the blocked state of a tab changes.
-  // NOTE: This is invoked when a tab becomes blocked/unblocked by a tab modal
-  // window.
-  virtual void TabBlockedStateChanged(TabContents* contents, int index);
-
-  // The TabStripModel now no longer has any phantom tabs. The implementer may
-  // use this as a trigger to try and close the window containing the
-  // TabStripModel, for example...
-  virtual void TabStripEmpty();
-
-  // Sent when the tabstrip model is about to be deleted and any reference held
-  // must be dropped.
-  virtual void TabStripModelDeleted();
-
- protected:
-  virtual ~TabStripModelObserver() {}
-};
-
-///////////////////////////////////////////////////////////////////////////////
-//
-// TabStripModelDelegate
-//
-//  A delegate interface that the TabStripModel uses to perform work that it
-//  can't do itself, such as obtain a container HWND for creating new
-//  TabContents, creating new TabStripModels for detached tabs, etc.
-//
-//  This interface is typically implemented by the controller that instantiates
-//  the TabStripModel (in our case the Browser object).
-//
-///////////////////////////////////////////////////////////////////////////////
-class TabStripModelDelegate {
- public:
-  // Adds what the delegate considers to be a blank tab to the model.
-  virtual TabContents* AddBlankTab(bool foreground) = 0;
-  virtual TabContents* AddBlankTabAt(int index, bool foreground) = 0;
-
-  // Asks for a new TabStripModel to be created and the given tab contents to
-  // be added to it. Its size and position are reflected in |window_bounds|.
-  // If |dock_info|'s type is other than NONE, the newly created window should
-  // be docked as identified by |dock_info|. Returns the Browser object
-  // representing the newly created window and tab strip. This does not
-  // show the window, it's up to the caller to do so.
-  virtual Browser* CreateNewStripWithContents(TabContents* contents,
-                                              const gfx::Rect& window_bounds,
-                                              const DockInfo& dock_info,
-                                              bool maximize) = 0;
-
-  // Creates a new Browser object and window containing the specified
-  // |contents|, and continues a drag operation that began within the source
-  // window's tab strip. |window_bounds| are the bounds of the source window in
-  // screen coordinates, used to place the new window, and |tab_bounds| are the
-  // bounds of the dragged Tab view in the source window, in screen coordinates,
-  // used to place the new Tab in the new window.
-  virtual void ContinueDraggingDetachedTab(TabContents* contents,
-                                           const gfx::Rect& window_bounds,
-                                           const gfx::Rect& tab_bounds) = 0;
-
-  enum {
-    TAB_MOVE_ACTION = 1,
-    TAB_TEAROFF_ACTION = 2
-  };
-
-  // Determines what drag actions are possible for the specified strip.
-  virtual int GetDragActions() const = 0;
-
-  // Creates an appropriate TabContents for the given URL. This is handled by
-  // the delegate since the TabContents may require special circumstances to
-  // exist for it to be constructed (e.g. a parent HWND).
-  // If |defer_load| is true, the navigation controller doesn't load the url.
-  // If |instance| is not null, its process is used to render the tab.
-  virtual TabContents* CreateTabContentsForURL(
-      const GURL& url,
-      const GURL& referrer,
-      Profile* profile,
-      PageTransition::Type transition,
-      bool defer_load,
-      SiteInstance* instance) const = 0;
-
-  // Returns whether some contents can be duplicated.
-  virtual bool CanDuplicateContentsAt(int index) = 0;
-
-  // Duplicates the contents at the provided index and places it into its own
-  // window.
-  virtual void DuplicateContentsAt(int index) = 0;
-
-  // Called when a drag session has completed and the frame that initiated the
-  // the session should be closed.
-  virtual void CloseFrameAfterDragSession() = 0;
-
-  // Creates an entry in the historical tab database for the specified
-  // TabContents.
-  virtual void CreateHistoricalTab(TabContents* contents) = 0;
-
-  // Runs any unload listeners associated with the specified TabContents before
-  // it is closed. If there are unload listeners that need to be run, this
-  // function returns true and the TabStripModel will wait before closing the
-  // TabContents. If it returns false, there are no unload listeners and the
-  // TabStripModel can close the TabContents immediately.
-  virtual bool RunUnloadListenerBeforeClosing(TabContents* contents) = 0;
-
-  // Returns true if a tab can be restored.
-  virtual bool CanRestoreTab() = 0;
-
-  // Restores the last closed tab if CanRestoreTab would return true.
-  virtual void RestoreTab() = 0;
-
-  // Returns whether some contents can be closed.
-  virtual bool CanCloseContentsAt(int index) = 0;
-
-  // Returns true if we should allow "bookmark all tabs" in this window; this is
-  // true when there is more than one bookmarkable tab open.
-  virtual bool CanBookmarkAllTabs() const = 0;
-
-  // Creates a bookmark folder containing a bookmark for all open tabs.
-  virtual void BookmarkAllTabs() = 0;
-
-  // Returns true if any of the tabs can be closed.
-  virtual bool CanCloseTab() const;
-
-  // Returns true if the vertical tabstrip presentation should be used.
-  virtual bool UseVerticalTabs() const = 0;
-
-  // Toggles the use of the vertical tabstrip.
-  virtual void ToggleUseVerticalTabs() = 0;
-
-  // Returns true if the tab strip can use large icons.
-  virtual bool LargeIconsPermitted() const = 0;
-
- protected:
-  virtual ~TabStripModelDelegate() {}
-};
 
 ////////////////////////////////////////////////////////////////////////////////
 //
diff --git a/chrome/browser/tabs/tab_strip_model_delegate.h b/chrome/browser/tabs/tab_strip_model_delegate.h
new file mode 100644
index 0000000..4901bbe
--- /dev/null
+++ b/chrome/browser/tabs/tab_strip_model_delegate.h
@@ -0,0 +1,135 @@
+// Copyright (c) 2010 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 CHROME_BROWSER_TABS_TAB_STRIP_MODEL_DELEGATE_H_
+#define CHROME_BROWSER_TABS_TAB_STRIP_MODEL_DELEGATE_H_
+#pragma once
+
+#include "chrome/common/page_transition_types.h"
+
+class Browser;
+class DockInfo;
+class GURL;
+class Profile;
+class SiteInstance;
+class TabContents;
+namespace gfx {
+class Rect;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+//
+// TabStripModelDelegate
+//
+//  A delegate interface that the TabStripModel uses to perform work that it
+//  can't do itself, such as obtain a container HWND for creating new
+//  TabContents, creating new TabStripModels for detached tabs, etc.
+//
+//  This interface is typically implemented by the controller that instantiates
+//  the TabStripModel (in our case the Browser object).
+//
+///////////////////////////////////////////////////////////////////////////////
+class TabStripModelDelegate {
+ public:
+  enum {
+    TAB_MOVE_ACTION = 1,
+    TAB_TEAROFF_ACTION = 2
+  };
+
+  // Adds what the delegate considers to be a blank tab to the model.
+  virtual TabContents* AddBlankTab(bool foreground) = 0;
+  virtual TabContents* AddBlankTabAt(int index, bool foreground) = 0;
+
+  // Asks for a new TabStripModel to be created and the given tab contents to
+  // be added to it. Its size and position are reflected in |window_bounds|.
+  // If |dock_info|'s type is other than NONE, the newly created window should
+  // be docked as identified by |dock_info|. Returns the Browser object
+  // representing the newly created window and tab strip. This does not
+  // show the window, it's up to the caller to do so.
+  virtual Browser* CreateNewStripWithContents(TabContents* contents,
+                                              const gfx::Rect& window_bounds,
+                                              const DockInfo& dock_info,
+                                              bool maximize) = 0;
+
+  // Creates a new Browser object and window containing the specified
+  // |contents|, and continues a drag operation that began within the source
+  // window's tab strip. |window_bounds| are the bounds of the source window in
+  // screen coordinates, used to place the new window, and |tab_bounds| are the
+  // bounds of the dragged Tab view in the source window, in screen coordinates,
+  // used to place the new Tab in the new window.
+  virtual void ContinueDraggingDetachedTab(TabContents* contents,
+                                           const gfx::Rect& window_bounds,
+                                           const gfx::Rect& tab_bounds) = 0;
+
+  // Determines what drag actions are possible for the specified strip.
+  virtual int GetDragActions() const = 0;
+
+  // Creates an appropriate TabContents for the given URL. This is handled by
+  // the delegate since the TabContents may require special circumstances to
+  // exist for it to be constructed (e.g. a parent HWND).
+  // If |defer_load| is true, the navigation controller doesn't load the url.
+  // If |instance| is not null, its process is used to render the tab.
+  virtual TabContents* CreateTabContentsForURL(
+      const GURL& url,
+      const GURL& referrer,
+      Profile* profile,
+      PageTransition::Type transition,
+      bool defer_load,
+      SiteInstance* instance) const = 0;
+
+  // Returns whether some contents can be duplicated.
+  virtual bool CanDuplicateContentsAt(int index) = 0;
+
+  // Duplicates the contents at the provided index and places it into its own
+  // window.
+  virtual void DuplicateContentsAt(int index) = 0;
+
+  // Called when a drag session has completed and the frame that initiated the
+  // the session should be closed.
+  virtual void CloseFrameAfterDragSession() = 0;
+
+  // Creates an entry in the historical tab database for the specified
+  // TabContents.
+  virtual void CreateHistoricalTab(TabContents* contents) = 0;
+
+  // Runs any unload listeners associated with the specified TabContents before
+  // it is closed. If there are unload listeners that need to be run, this
+  // function returns true and the TabStripModel will wait before closing the
+  // TabContents. If it returns false, there are no unload listeners and the
+  // TabStripModel can close the TabContents immediately.
+  virtual bool RunUnloadListenerBeforeClosing(TabContents* contents) = 0;
+
+  // Returns true if a tab can be restored.
+  virtual bool CanRestoreTab() = 0;
+
+  // Restores the last closed tab if CanRestoreTab would return true.
+  virtual void RestoreTab() = 0;
+
+  // Returns whether some contents can be closed.
+  virtual bool CanCloseContentsAt(int index) = 0;
+
+  // Returns true if we should allow "bookmark all tabs" in this window; this is
+  // true when there is more than one bookmarkable tab open.
+  virtual bool CanBookmarkAllTabs() const = 0;
+
+  // Creates a bookmark folder containing a bookmark for all open tabs.
+  virtual void BookmarkAllTabs() = 0;
+
+  // Returns true if any of the tabs can be closed.
+  virtual bool CanCloseTab() const = 0;
+
+  // Returns true if the vertical tabstrip presentation should be used.
+  virtual bool UseVerticalTabs() const = 0;
+
+  // Toggles the use of the vertical tabstrip.
+  virtual void ToggleUseVerticalTabs() = 0;
+
+  // Returns true if the tab strip can use large icons.
+  virtual bool LargeIconsPermitted() const = 0;
+
+ protected:
+  virtual ~TabStripModelDelegate() {}
+};
+
+#endif  // CHROME_BROWSER_TABS_TAB_STRIP_MODEL_DELEGATE_H_
diff --git a/chrome/browser/tabs/tab_strip_model_observer.cc b/chrome/browser/tabs/tab_strip_model_observer.cc
new file mode 100644
index 0000000..c3bfb9b
--- /dev/null
+++ b/chrome/browser/tabs/tab_strip_model_observer.cc
@@ -0,0 +1,62 @@
+// Copyright (c) 2010 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/tabs/tab_strip_model_observer.h"
+
+void TabStripModelObserver::TabInsertedAt(TabContents* contents,
+                                          int index,
+                                          bool foreground) {
+}
+
+void TabStripModelObserver::TabClosingAt(TabContents* contents, int index) {
+}
+
+void TabStripModelObserver::TabDetachedAt(TabContents* contents, int index) {
+}
+
+void TabStripModelObserver::TabDeselectedAt(TabContents* contents, int index) {
+}
+
+void TabStripModelObserver::TabSelectedAt(TabContents* old_contents,
+                                          TabContents* new_contents,
+                                          int index,
+                                          bool user_gesture) {
+}
+
+void TabStripModelObserver::TabMoved(TabContents* contents,
+                                     int from_index,
+                                     int to_index) {
+}
+
+void TabStripModelObserver::TabChangedAt(TabContents* contents, int index,
+                                         TabChangeType change_type) {
+}
+
+void TabStripModelObserver::TabReplacedAt(TabContents* old_contents,
+                                          TabContents* new_contents,
+                                          int index) {
+}
+
+void TabStripModelObserver::TabReplacedAt(TabContents* old_contents,
+                                          TabContents* new_contents,
+                                          int index,
+                                          TabReplaceType type) {
+  TabReplacedAt(old_contents, new_contents, index);
+}
+
+void TabStripModelObserver::TabPinnedStateChanged(TabContents* contents,
+                                                  int index) {
+}
+
+void TabStripModelObserver::TabMiniStateChanged(TabContents* contents,
+                                                int index) {
+}
+
+void TabStripModelObserver::TabBlockedStateChanged(TabContents* contents,
+                                                   int index) {
+}
+
+void TabStripModelObserver::TabStripEmpty() {}
+
+void TabStripModelObserver::TabStripModelDeleted() {}
diff --git a/chrome/browser/tabs/tab_strip_model_observer.h b/chrome/browser/tabs/tab_strip_model_observer.h
new file mode 100644
index 0000000..cfbf9e8
--- /dev/null
+++ b/chrome/browser/tabs/tab_strip_model_observer.h
@@ -0,0 +1,142 @@
+// Copyright (c) 2010 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 CHROME_BROWSER_TABS_TAB_STRIP_MODEL_OBSERVER_H_
+#define CHROME_BROWSER_TABS_TAB_STRIP_MODEL_OBSERVER_H_
+#pragma once
+
+class TabContents;
+
+////////////////////////////////////////////////////////////////////////////////
+//
+// TabStripModelObserver
+//
+//  Objects implement this interface when they wish to be notified of changes
+//  to the TabStripModel.
+//
+//  Two major implementers are the TabStrip, which uses notifications sent
+//  via this interface to update the presentation of the strip, and the Browser
+//  object, which updates bookkeeping and shows/hides individual TabContentses.
+//
+//  Register your TabStripModelObserver with the TabStripModel using its
+//  Add/RemoveObserver methods.
+//
+////////////////////////////////////////////////////////////////////////////////
+class TabStripModelObserver {
+ public:
+  // Enumeration of the possible values supplied to TabChangedAt.
+  enum TabChangeType {
+    // Only the loading state changed.
+    LOADING_ONLY,
+
+    // Only the title changed and page isn't loading.
+    TITLE_NOT_LOADING,
+
+    // Change not characterized by LOADING_ONLY or TITLE_NOT_LOADING.
+    ALL
+  };
+
+  // Enum used by ReplaceTabContentsAt.
+  // TODO(sky): nuke this, pinned is being removed so there is no point in the
+  // enum.
+  enum TabReplaceType {
+    // The replace is the result of the tab being made phantom.
+    REPLACE_MADE_PHANTOM,
+
+    // The replace is the result of the match preview being committed.
+    REPLACE_MATCH_PREVIEW
+  };
+
+  // A new TabContents was inserted into the TabStripModel at the specified
+  // index. |foreground| is whether or not it was opened in the foreground
+  // (selected).
+  virtual void TabInsertedAt(TabContents* contents,
+                             int index,
+                             bool foreground);
+
+  // The specified TabContents at |index| is being closed (and eventually
+  // destroyed).
+  virtual void TabClosingAt(TabContents* contents, int index);
+
+  // The specified TabContents at |index| is being detached, perhaps to be
+  // inserted in another TabStripModel. The implementer should take whatever
+  // action is necessary to deal with the TabContents no longer being present.
+  virtual void TabDetachedAt(TabContents* contents, int index);
+
+  // The selected TabContents is about to change from |old_contents| at |index|.
+  // This gives observers a chance to prepare for an impending switch before it
+  // happens.
+  virtual void TabDeselectedAt(TabContents* contents, int index);
+
+  // The selected TabContents changed from |old_contents| to |new_contents| at
+  // |index|. |user_gesture| specifies whether or not this was done by a user
+  // input event (e.g. clicking on a tab, keystroke) or as a side-effect of
+  // some other function.
+  virtual void TabSelectedAt(TabContents* old_contents,
+                             TabContents* new_contents,
+                             int index,
+                             bool user_gesture);
+
+  // The specified TabContents at |from_index| was moved to |to_index|.
+  virtual void TabMoved(TabContents* contents,
+                        int from_index,
+                        int to_index);
+
+  // The specified TabContents at |index| changed in some way. |contents| may
+  // be an entirely different object and the old value is no longer available
+  // by the time this message is delivered.
+  //
+  // See TabChangeType for a description of |change_type|.
+  virtual void TabChangedAt(TabContents* contents,
+                            int index,
+                            TabChangeType change_type);
+
+  // The tab contents was replaced at the specified index. This is invoked when
+  // a tab becomes phantom. See description of phantom tabs in class description
+  // of TabStripModel for details.
+  // TODO(sky): nuke this in favor of the 4 arg variant.
+  virtual void TabReplacedAt(TabContents* old_contents,
+                             TabContents* new_contents,
+                             int index);
+
+  // The tab contents was replaced at the specified index. |type| describes
+  // the type of replace.
+  // This invokes TabReplacedAt with three args.
+  virtual void TabReplacedAt(TabContents* old_contents,
+                             TabContents* new_contents,
+                             int index,
+                             TabReplaceType type);
+
+  // Invoked when the pinned state of a tab changes. This is not invoked if the
+  // tab ends up moving as a result of the mini state changing.
+  // See note in TabMiniStateChanged as to how this relates to
+  // TabMiniStateChanged.
+  virtual void TabPinnedStateChanged(TabContents* contents, int index);
+
+  // Invoked if the mini state of a tab changes.  This is not invoked if the
+  // tab ends up moving as a result of the mini state changing.
+  // NOTE: this is sent when the pinned state of a non-app tab changes and is
+  // sent in addition to TabPinnedStateChanged. UI code typically need not care
+  // about TabPinnedStateChanged, but instead this.
+  virtual void TabMiniStateChanged(TabContents* contents, int index);
+
+  // Invoked when the blocked state of a tab changes.
+  // NOTE: This is invoked when a tab becomes blocked/unblocked by a tab modal
+  // window.
+  virtual void TabBlockedStateChanged(TabContents* contents, int index);
+
+  // The TabStripModel now no longer has any phantom tabs. The implementer may
+  // use this as a trigger to try and close the window containing the
+  // TabStripModel, for example...
+  virtual void TabStripEmpty();
+
+  // Sent when the tabstrip model is about to be deleted and any reference held
+  // must be dropped.
+  virtual void TabStripModelDeleted();
+
+ protected:
+  virtual ~TabStripModelObserver() {}
+};
+
+#endif  // CHROME_BROWSER_TABS_TAB_STRIP_MODEL_OBSERVER_H_
diff --git a/chrome/browser/tabs/tab_strip_model_unittest.cc b/chrome/browser/tabs/tab_strip_model_unittest.cc
index 51924cf..9fabf5b 100644
--- a/chrome/browser/tabs/tab_strip_model_unittest.cc
+++ b/chrome/browser/tabs/tab_strip_model_unittest.cc
@@ -22,6 +22,7 @@
 #include "chrome/browser/tab_contents/navigation_entry.h"
 #include "chrome/browser/tab_contents/tab_contents.h"
 #include "chrome/browser/tabs/tab_strip_model.h"
+#include "chrome/browser/tabs/tab_strip_model_delegate.h"
 #include "chrome/browser/tabs/tab_strip_model_order_controller.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/notification_observer_mock.h"
@@ -83,6 +84,7 @@ class TabStripDummyDelegate : public TabStripModelDelegate {
   virtual bool CanCloseContentsAt(int index) { return can_close_ ; }
   virtual bool CanBookmarkAllTabs() const { return false; }
   virtual void BookmarkAllTabs() {}
+  virtual bool CanCloseTab() const { return true; }
   virtual bool UseVerticalTabs() const { return false; }
   virtual void ToggleUseVerticalTabs() {}
   virtual bool LargeIconsPermitted() const { return true; }