Introduce BrowserIterator.

An iterator meant to iterate over all the browsers in BrowserListImpls across multiple desktops (i.e. multiple HostDesktopTypes).

As a first step, used it in TabContentsIterator (pretty much bringing back the implementation to the one that was there prior to https://codereview.chromium.org/11316340/ -- except that the iterator is now aware of multiple desktops).

Another CL will follow in which all BrowserList::const_iterator, etc. methods will be replaced by BrowserIterator.

The interface of BrowserIterator is derived from the interface of TabContentsIterator for consistency (which is being slightly tweaked in parallel in https://codereview.chromium.org/12049038/).

BUG=129187

Review URL: https://chromiumcodereview.appspot.com/12038053

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@179695 0039d316-1c4b-4281-b951-d872f2087c98

10 files changed, 315 insertions, 82 deletions

diff --git a/chrome/browser/ui/browser_iterator.cc b/chrome/browser/ui/browser_iterator.cc
new file mode 100644
index 0000000..73571d5
--- /dev/null
+++ b/chrome/browser/ui/browser_iterator.cc
@@ -0,0 +1,33 @@
+// Copyright (c) 2013 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/browser_iterator.h"
+
+namespace chrome {
+
+BrowserIterator::BrowserIterator()
+    : current_browser_list_(
+          BrowserListImpl::GetInstance(HOST_DESKTOP_TYPE_FIRST)),
+      current_iterator_(current_browser_list_->begin()),
+      next_desktop_type_(
+          static_cast<HostDesktopType>(HOST_DESKTOP_TYPE_FIRST + 1)) {
+  NextBrowserListIfAtEnd();
+}
+
+void BrowserIterator::Next() {
+  ++current_iterator_;
+  NextBrowserListIfAtEnd();
+}
+
+void BrowserIterator::NextBrowserListIfAtEnd() {
+  // Make sure either |current_iterator_| is valid or done().
+  while (current_iterator_ == current_browser_list_->end() &&
+         next_desktop_type_ < HOST_DESKTOP_TYPE_COUNT) {
+    current_browser_list_ = BrowserListImpl::GetInstance(next_desktop_type_);
+    current_iterator_ = current_browser_list_->begin();
+    next_desktop_type_ = static_cast<HostDesktopType>(next_desktop_type_ + 1);
+  }
+}
+
+}  // namespace chrome
diff --git a/chrome/browser/ui/browser_iterator.h b/chrome/browser/ui/browser_iterator.h
new file mode 100644
index 0000000..4911679
--- /dev/null
+++ b/chrome/browser/ui/browser_iterator.h
@@ -0,0 +1,71 @@
+// Copyright (c) 2013 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_UI_BROWSER_ITERATOR_H_
+#define CHROME_BROWSER_UI_BROWSER_ITERATOR_H_
+
+#include "chrome/browser/ui/browser_list_impl.h"
+#include "chrome/browser/ui/host_desktop.h"
+
+class Browser;
+
+namespace chrome {
+
+// Iterates over all existing browsers (potentially across multiple desktops).
+// Note: to iterate only over the browsers of a specific desktop, use the
+// const_iterator of a given BrowserListImpl instead.
+//
+// Example:
+//   for (BrowserIterator iterator; !iterator.done(); iterator.Next()) {
+//     Browser* cur = *iterator;
+//     -or-
+//     iterator->OperationOnBrowser();
+//     ...
+//   }
+class BrowserIterator {
+ public:
+  BrowserIterator();
+
+  // Returns true if we are past the last Browser.
+  bool done() const {
+    // |current_iterator_| is never at the end of a list unless it is done (it
+    // immediately moves to the next browser list upon hitting the end of the
+    // current list unless there are no remaining empty browser lists).
+    return current_iterator_ == current_browser_list_->end();
+  }
+
+  // Returns the current Browser, valid as long as !done().
+  Browser* operator->() const {
+    return *current_iterator_;
+  }
+  Browser* operator*() const {
+    return *current_iterator_;
+  }
+
+  // Advances |current_iterator_| to the next browser.
+  void Next();
+
+ private:
+  // If |current_iterator_| is at |current_browser_list_->end()|, advance to the
+  // next non-empty browser list. After a call to this method: either
+  // |current_iterator_| is valid or done().
+  void NextBrowserListIfAtEnd();
+
+  // The BrowserListImpl currently being iterated over. Instances of this class
+  // do not own this pointer.
+  BrowserListImpl* current_browser_list_;
+
+  // The underlying iterator over browsers in |current_browser_list_|.
+  BrowserListImpl::const_iterator current_iterator_;
+
+  // The next HostDesktopType to iterate over when |current_iterator_| reaches
+  // |current_browser_list_->end()|.
+  HostDesktopType next_desktop_type_;
+
+  DISALLOW_COPY_AND_ASSIGN(BrowserIterator);
+};
+
+}  // namespace chrome
+
+#endif  // CHROME_BROWSER_UI_BROWSER_ITERATOR_H_
diff --git a/chrome/browser/ui/browser_iterator_unittest.cc b/chrome/browser/ui/browser_iterator_unittest.cc
new file mode 100644
index 0000000..33d3be2
--- /dev/null
+++ b/chrome/browser/ui/browser_iterator_unittest.cc
@@ -0,0 +1,122 @@
+// Copyright (c) 2013 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/browser_iterator.h"
+
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_list_impl.h"
+#include "chrome/browser/ui/host_desktop.h"
+#include "chrome/test/base/browser_with_test_window_test.h"
+
+typedef BrowserWithTestWindowTest BrowserIteratorTest;
+
+namespace {
+
+// BrowserWithTestWindowTest's default window is on the native desktop by
+// default. Force it to be on the Ash desktop to be able to test the iterator
+// in a situation with no browsers on the native desktop.
+class BrowserIteratorTestWithInitialWindowInAsh
+    : public BrowserWithTestWindowTest {
+ public:
+  BrowserIteratorTestWithInitialWindowInAsh()
+      : BrowserWithTestWindowTest(chrome::HOST_DESKTOP_TYPE_ASH) {
+  }
+};
+
+// Helper function to iterate and count all the browsers.
+size_t CountAllBrowsers() {
+  size_t count = 0;
+  for (chrome::BrowserIterator iterator; !iterator.done(); iterator.Next())
+    ++count;
+  return count;
+}
+
+}
+
+TEST_F(BrowserIteratorTest, BrowsersOnMultipleDesktops) {
+  Browser::CreateParams native_params(profile(),
+                                      chrome::HOST_DESKTOP_TYPE_NATIVE);
+  Browser::CreateParams ash_params(profile(), chrome::HOST_DESKTOP_TYPE_ASH);
+  // Note, browser 1 is on the native desktop.
+  scoped_ptr<Browser> browser2(
+      chrome::CreateBrowserWithTestWindowForParams(&native_params));
+  scoped_ptr<Browser> browser3(
+      chrome::CreateBrowserWithTestWindowForParams(&native_params));
+  scoped_ptr<Browser> browser4(
+      chrome::CreateBrowserWithTestWindowForParams(&ash_params));
+  scoped_ptr<Browser> browser5(
+      chrome::CreateBrowserWithTestWindowForParams(&ash_params));
+
+  // Sanity checks.
+  chrome::BrowserListImpl* native_list =
+      chrome::BrowserListImpl::GetInstance(chrome::HOST_DESKTOP_TYPE_NATIVE);
+#if defined(OS_CHROMEOS)
+  // On Chrome OS, the native list and the ash list are the same.
+  EXPECT_EQ(5U, native_list->size());
+#else
+  chrome::BrowserListImpl* ash_list =
+      chrome::BrowserListImpl::GetInstance(chrome::HOST_DESKTOP_TYPE_ASH);
+  EXPECT_EQ(3U, native_list->size());
+  EXPECT_EQ(2U, ash_list->size());
+#endif
+
+  // Make sure the iterator finds all 5 browsers regardless of which desktop
+  // they are on.
+  EXPECT_EQ(5U, CountAllBrowsers());
+}
+
+TEST_F(BrowserIteratorTest, NoBrowsersOnAshDesktop) {
+  Browser::CreateParams native_params(profile(),
+                                      chrome::HOST_DESKTOP_TYPE_NATIVE);
+  // Note, browser 1 is on the native desktop.
+  scoped_ptr<Browser> browser2(
+      chrome::CreateBrowserWithTestWindowForParams(&native_params));
+  scoped_ptr<Browser> browser3(
+      chrome::CreateBrowserWithTestWindowForParams(&native_params));
+
+  // Sanity checks.
+  chrome::BrowserListImpl* native_list =
+      chrome::BrowserListImpl::GetInstance(chrome::HOST_DESKTOP_TYPE_NATIVE);
+  EXPECT_EQ(3U, native_list->size());
+#if !defined(OS_CHROMEOS)
+  // On non-Chrome OS platforms the Ash list is independent from the native
+  // list, double-check that it's empty.
+  chrome::BrowserListImpl* ash_list =
+      chrome::BrowserListImpl::GetInstance(chrome::HOST_DESKTOP_TYPE_ASH);
+  EXPECT_EQ(0U, ash_list->size());
+#endif
+
+  // Make sure the iterator finds all 3 browsers on the native desktop and
+  // doesn't trip over the empty Ash desktop list.
+  EXPECT_EQ(3U, CountAllBrowsers());
+}
+
+TEST_F(BrowserIteratorTestWithInitialWindowInAsh, NoBrowsersOnNativeDesktop) {
+  Browser::CreateParams ash_params(profile(), chrome::HOST_DESKTOP_TYPE_ASH);
+  // Note, browser 1 is on the ash desktop.
+  scoped_ptr<Browser> browser2(
+      chrome::CreateBrowserWithTestWindowForParams(&ash_params));
+  scoped_ptr<Browser> browser3(
+      chrome::CreateBrowserWithTestWindowForParams(&ash_params));
+
+  chrome::BrowserListImpl* ash_list =
+      chrome::BrowserListImpl::GetInstance(chrome::HOST_DESKTOP_TYPE_ASH);
+  EXPECT_EQ(3U, ash_list->size());
+#if !defined(OS_CHROMEOS)
+  // On non-Chrome OS platforms the native list is independent from the Ash
+  // list; double-check that it's empty.
+  chrome::BrowserListImpl* native_list =
+      chrome::BrowserListImpl::GetInstance(chrome::HOST_DESKTOP_TYPE_NATIVE);
+  EXPECT_EQ(0U, native_list->size());
+#endif
+
+  // Make sure the iterator finds all 3 browsers on the ash desktop and
+  // doesn't trip over the empty native desktop list.
+  EXPECT_EQ(3U, CountAllBrowsers());
+}
+
+// Verify that the iterator still behaves if there are no browsers at all.
+TEST(BrowserIteratorTestWithNoTestWindow, NoBrowser) {
+  EXPECT_EQ(0U, CountAllBrowsers());
+}
diff --git a/chrome/browser/ui/tab_contents/tab_contents_iterator.cc b/chrome/browser/ui/tab_contents/tab_contents_iterator.cc
index e8b5034..bc03577 100644
--- a/chrome/browser/ui/tab_contents/tab_contents_iterator.cc
+++ b/chrome/browser/ui/tab_contents/tab_contents_iterator.cc
@@ -11,68 +11,31 @@
 
 TabContentsIterator::TabContentsIterator()
     : web_view_index_(-1),
-      cur_(NULL),
-      desktop_browser_list_(chrome::BrowserListImpl::GetInstance(
-          chrome::HOST_DESKTOP_TYPE_NATIVE)),
-      ash_browser_list_(chrome::BrowserListImpl::GetInstance(
-          chrome::HOST_DESKTOP_TYPE_ASH)),
-      desktop_browser_iterator_(desktop_browser_list_->begin()),
-      ash_browser_iterator_(ash_browser_list_->begin()) {
+      cur_(NULL) {
   // Load the first WebContents into |cur_|.
   Next();
 }
 
-Browser* TabContentsIterator::browser() const {
-  if (desktop_browser_iterator_ != desktop_browser_list_->end())
-    return *desktop_browser_iterator_;
-  // In some cases like Chrome OS the two browser lists are the same.
-  if (desktop_browser_list_ != ash_browser_list_) {
-    if (ash_browser_iterator_ != ash_browser_list_->end())
-      return *ash_browser_iterator_;
-  }
-  return NULL;
-}
-
 void TabContentsIterator::Next() {
   // The current WebContents should be valid unless we are at the beginning.
-  DCHECK(cur_ || (web_view_index_ == -1 &&
-            desktop_browser_iterator_ == desktop_browser_list_->begin() &&
-            ash_browser_iterator_ == ash_browser_list_->begin()))
-      << "Trying to advance past the end";
-
-  // First iterate over the Browser objects in the desktop environment and then
-  // over those in the ASH environment.
-  if (AdvanceBrowserIterator(&desktop_browser_iterator_,
-                             desktop_browser_list_))
-    return;
-
-  // In some cases like Chrome OS the two browser lists are the same.
-  if (desktop_browser_list_ != ash_browser_list_)
-    AdvanceBrowserIterator(&ash_browser_iterator_, ash_browser_list_);
-}
+  DCHECK(cur_ || web_view_index_ == -1) << "Trying to advance past the end";
 
-bool TabContentsIterator::AdvanceBrowserIterator(
-    chrome::BrowserListImpl::const_iterator* list_iterator,
-    chrome::BrowserListImpl* browser_list) {
-  // Update cur_ to the next WebContents in the list.
-  while (*list_iterator != browser_list->end()) {
-    if (++web_view_index_ >=
-          (**list_iterator)->tab_strip_model()->count()) {
+  // Update |cur_| to the next WebContents in the list.
+  while (!browser_iterator_.done()) {
+    if (++web_view_index_ >= browser_iterator_->tab_strip_model()->count()) {
       // Advance to the next Browser in the list.
-      ++(*list_iterator);
+      browser_iterator_.Next();
       web_view_index_ = -1;
       continue;
     }
 
-    content::WebContents* next_tab =
-        (**list_iterator)->tab_strip_model()->GetWebContentsAt(
-            web_view_index_);
+    content::WebContents* next_tab = browser_iterator_->tab_strip_model()
+        ->GetWebContentsAt(web_view_index_);
     if (next_tab) {
       cur_ = next_tab;
-      return true;
+      return;
     }
   }
   // Reached the end.
   cur_ = NULL;
-  return false;
 }
diff --git a/chrome/browser/ui/tab_contents/tab_contents_iterator.h b/chrome/browser/ui/tab_contents/tab_contents_iterator.h
index 76ad9c2..818658f 100644
--- a/chrome/browser/ui/tab_contents/tab_contents_iterator.h
+++ b/chrome/browser/ui/tab_contents/tab_contents_iterator.h
@@ -8,8 +8,7 @@
 #include <set>
 
 #include "base/basictypes.h"
-#include "chrome/browser/ui/browser_list_impl.h"
-#include "chrome/browser/ui/host_desktop.h"
+#include "chrome/browser/ui/browser_iterator.h"
 
 namespace content {
 class WebContents;
@@ -36,7 +35,11 @@ class TabContentsIterator {
 
   // Returns the Browser instance associated with the current
   // WebContents. Valid as long as !done().
-  Browser* browser() const;
+  Browser* browser() const {
+    if (!browser_iterator_.done())
+      return *browser_iterator_;
+    return NULL;
+  }
 
   // Returns the current WebContents, valid as long as !done().
   content::WebContents* operator->() const {
@@ -52,13 +55,6 @@ class TabContentsIterator {
   void Next();
 
  private:
-  // Helper function to iterate the BrowserList passed in.
-  // Returns true if the iterator was successfully advanced.
-  // TODO(gab): Remove this method when introducing BrowserIterator.
-  bool AdvanceBrowserIterator(
-      chrome::BrowserListImpl::const_iterator* list_iterator,
-      chrome::BrowserListImpl* browser_list);
-
   // Tab index into the current Browser of the current web view.
   int web_view_index_;
 
@@ -67,17 +63,8 @@ class TabContentsIterator {
   // cache this since the caller may access the current host many times.
   content::WebContents* cur_;
 
-  // The Desktop Browser list.
-  chrome::BrowserListImpl* desktop_browser_list_;
-
-  // The Ash Browser list.
-  chrome::BrowserListImpl* ash_browser_list_;
-
-  // Iterator over all the Browser objects in desktop mode.
-  chrome::BrowserListImpl::const_iterator desktop_browser_iterator_;
-
-  // Iterator over all the Browser objects in Ash mode.
-  chrome::BrowserListImpl::const_iterator ash_browser_iterator_;
+  // An iterator over all the browsers.
+  chrome::BrowserIterator browser_iterator_;
 
   DISALLOW_COPY_AND_ASSIGN(TabContentsIterator);
 };
diff --git a/chrome/browser/ui/tab_contents/tab_contents_iterator_unittest.cc b/chrome/browser/ui/tab_contents/tab_contents_iterator_unittest.cc
index 616ed65..9f300bc 100644
--- a/chrome/browser/ui/tab_contents/tab_contents_iterator_unittest.cc
+++ b/chrome/browser/ui/tab_contents/tab_contents_iterator_unittest.cc
@@ -8,7 +8,8 @@
 #include "chrome/browser/browser_shutdown.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/ui/browser_commands.h"
-#include "chrome/browser/ui/browser_list.h"
+#include "chrome/browser/ui/browser_list_impl.h"
+#include "chrome/browser/ui/host_desktop.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/test/base/browser_with_test_window_test.h"
@@ -32,20 +33,33 @@ size_t CountAllTabs() {
 
 TEST_F(BrowserListTest, TabContentsIteratorVerifyCount) {
   // Make sure we have 1 window to start with.
-  EXPECT_EQ(1U, BrowserList::size());
+  EXPECT_EQ(1U, chrome::BrowserListImpl::GetInstance(
+                    chrome::HOST_DESKTOP_TYPE_NATIVE)->size());
 
   EXPECT_EQ(0U, CountAllTabs());
 
   // Create more browsers/windows.
   scoped_ptr<Browser> browser2(
       chrome::CreateBrowserWithTestWindowForProfile(profile()));
+  // Create browser 3 and 4 on the Ash desktop (the TabContentsIterator
+  // shouldn't see the difference).
+  Browser::CreateParams ash_params(profile(), chrome::HOST_DESKTOP_TYPE_ASH);
   scoped_ptr<Browser> browser3(
-      chrome::CreateBrowserWithTestWindowForProfile(profile()));
+      chrome::CreateBrowserWithTestWindowForParams(&ash_params));
   scoped_ptr<Browser> browser4(
-      chrome::CreateBrowserWithTestWindowForProfile(profile()));
+      chrome::CreateBrowserWithTestWindowForParams(&ash_params));
 
   // Sanity checks.
-  EXPECT_EQ(4U, BrowserList::size());
+#if defined(OS_CHROMEOS)
+  // The ash desktop is the native desktop on Chrome OS.
+  EXPECT_EQ(4U, chrome::BrowserListImpl::GetInstance(
+                    chrome::HOST_DESKTOP_TYPE_NATIVE)->size());
+#else
+  EXPECT_EQ(2U, chrome::BrowserListImpl::GetInstance(
+                    chrome::HOST_DESKTOP_TYPE_NATIVE)->size());
+  EXPECT_EQ(2U, chrome::BrowserListImpl::GetInstance(
+                    chrome::HOST_DESKTOP_TYPE_ASH)->size());
+#endif
   EXPECT_EQ(0, browser()->tab_strip_model()->count());
   EXPECT_EQ(0, browser2->tab_strip_model()->count());
   EXPECT_EQ(0, browser3->tab_strip_model()->count());
@@ -76,16 +90,29 @@ TEST_F(BrowserListTest, TabContentsIteratorVerifyCount) {
 
 TEST_F(BrowserListTest, TabContentsIteratorVerifyBrowser) {
   // Make sure we have 1 window to start with.
-  EXPECT_EQ(1U, BrowserList::size());
+  EXPECT_EQ(1U, chrome::BrowserListImpl::GetInstance(
+                    chrome::HOST_DESKTOP_TYPE_NATIVE)->size());
 
   // Create more browsers/windows.
   scoped_ptr<Browser> browser2(
       chrome::CreateBrowserWithTestWindowForProfile(profile()));
+  // Create browser 3 on the Ash desktop (the TabContentsIterator shouldn't see
+  // the difference).
+  Browser::CreateParams ash_params(profile(), chrome::HOST_DESKTOP_TYPE_ASH);
   scoped_ptr<Browser> browser3(
-      chrome::CreateBrowserWithTestWindowForProfile(profile()));
+      chrome::CreateBrowserWithTestWindowForParams(&ash_params));
 
   // Sanity checks.
-  EXPECT_EQ(3U, BrowserList::size());
+#if defined(OS_CHROMEOS)
+  // The ash desktop is the native desktop on Chrome OS.
+  EXPECT_EQ(3U, chrome::BrowserListImpl::GetInstance(
+                    chrome::HOST_DESKTOP_TYPE_NATIVE)->size());
+#else
+  EXPECT_EQ(2U, chrome::BrowserListImpl::GetInstance(
+                    chrome::HOST_DESKTOP_TYPE_NATIVE)->size());
+  EXPECT_EQ(1U, chrome::BrowserListImpl::GetInstance(
+                    chrome::HOST_DESKTOP_TYPE_ASH)->size());
+#endif
   EXPECT_EQ(0, browser()->tab_strip_model()->count());
   EXPECT_EQ(0, browser2->tab_strip_model()->count());
   EXPECT_EQ(0, browser3->tab_strip_model()->count());
@@ -95,21 +122,23 @@ TEST_F(BrowserListTest, TabContentsIteratorVerifyBrowser) {
   // Add some tabs.
   for (size_t i = 0; i < 3; ++i)
     chrome::NewTab(browser2.get());
-  chrome::NewTab(browser3.get());
+  for (size_t i = 0; i < 2; ++i)
+    chrome::NewTab(browser3.get());
 
   size_t count = 0;
   for (TabContentsIterator iterator; !iterator.done(); iterator.Next(),
                                                        ++count) {
     if (count < 3)
       EXPECT_EQ(browser2.get(), iterator.browser());
-    else if (count == 3)
+    else if (count < 5)
       EXPECT_EQ(browser3.get(), iterator.browser());
     else
-      EXPECT_TRUE(false);
+      ADD_FAILURE();
   }
 
   // Close some tabs.
   browser2->tab_strip_model()->CloseAllTabs();
+  browser3->tab_strip_model()->CloseWebContentsAt(1, TabStripModel::CLOSE_NONE);
 
   count = 0;
   for (TabContentsIterator iterator; !iterator.done(); iterator.Next(),
@@ -117,7 +146,7 @@ TEST_F(BrowserListTest, TabContentsIteratorVerifyBrowser) {
     if (count == 0)
       EXPECT_EQ(browser3.get(), iterator.browser());
     else
-      EXPECT_TRUE(false);
+      ADD_FAILURE();
   }
 
   // Now make it one tab per browser.
@@ -134,7 +163,7 @@ TEST_F(BrowserListTest, TabContentsIteratorVerifyBrowser) {
     else if (count == 2)
       EXPECT_EQ(browser3.get(), iterator.browser());
     else
-      EXPECT_TRUE(false);
+      ADD_FAILURE();
   }
 
   // Close all remaining tabs to keep all the destructors happy.
diff --git a/chrome/chrome_browser_ui.gypi b/chrome/chrome_browser_ui.gypi
index ba3fcbf..e093f62 100644
--- a/chrome/chrome_browser_ui.gypi
+++ b/chrome/chrome_browser_ui.gypi
@@ -256,6 +256,8 @@
         'browser/ui/browser_finder.h',
         'browser/ui/browser_instant_controller.cc',
         'browser/ui/browser_instant_controller.h',
+        'browser/ui/browser_iterator.cc',
+        'browser/ui/browser_iterator.h',
         'browser/ui/browser_list.cc',
         'browser/ui/browser_list.h',
         'browser/ui/browser_list_impl.cc',
@@ -2536,6 +2538,7 @@
             'browser/ui/browser.cc',
             'browser/ui/browser_command_controller.cc',
             'browser/ui/browser_finder.cc',
+            'browser/ui/browser_iterator.cc',
             'browser/ui/browser_list.cc',
             'browser/ui/browser_navigator.cc',
             'browser/ui/browser_otr_state.cc',
diff --git a/chrome/chrome_tests_unit.gypi b/chrome/chrome_tests_unit.gypi
index 4fa074c..d6b96b6 100644
--- a/chrome/chrome_tests_unit.gypi
+++ b/chrome/chrome_tests_unit.gypi
@@ -1180,6 +1180,7 @@
         'browser/ui/bookmarks/bookmark_prompt_controller_unittest.cc',
         'browser/ui/bookmarks/bookmark_ui_utils_unittest.cc',
         'browser/ui/browser_command_controller_unittest.cc',
+        'browser/ui/browser_iterator_unittest.cc',
         'browser/ui/chrome_select_file_policy_unittest.cc',
         # It is safe to list */cocoa/* files in the "common" file list
         # without an explicit exclusion since gyp is smart enough to
@@ -2126,6 +2127,7 @@
             'browser/ui/bookmarks/bookmark_context_menu_controller_unittest.cc',
             'browser/ui/bookmarks/bookmark_prompt_controller_unittest.cc',
             'browser/ui/browser_command_controller_unittest.cc',
+            'browser/ui/browser_iterator_unittest.cc',
             'browser/ui/fullscreen/fullscreen_controller_state_unittest.cc',
             'browser/ui/fullscreen/fullscreen_controller_unittest.cc',
             'browser/ui/search/search_delegate_unittest.cc',
diff --git a/chrome/test/base/browser_with_test_window_test.cc b/chrome/test/base/browser_with_test_window_test.cc
index 6e34bd22..9169439 100644
--- a/chrome/test/base/browser_with_test_window_test.cc
+++ b/chrome/test/base/browser_with_test_window_test.cc
@@ -32,7 +32,19 @@ BrowserWithTestWindowTest::BrowserWithTestWindowTest()
       db_thread_(BrowserThread::DB),
       file_thread_(BrowserThread::FILE, message_loop()),
       file_user_blocking_thread_(
-          BrowserThread::FILE_USER_BLOCKING, message_loop()) {
+          BrowserThread::FILE_USER_BLOCKING, message_loop()),
+      host_desktop_type_(chrome::HOST_DESKTOP_TYPE_NATIVE) {
+  db_thread_.Start();
+}
+
+BrowserWithTestWindowTest::BrowserWithTestWindowTest(
+    chrome::HostDesktopType host_desktop_type)
+    : ui_thread_(BrowserThread::UI, message_loop()),
+      db_thread_(BrowserThread::DB),
+      file_thread_(BrowserThread::FILE, message_loop()),
+      file_user_blocking_thread_(
+          BrowserThread::FILE_USER_BLOCKING, message_loop()),
+      host_desktop_type_(host_desktop_type) {
   db_thread_.Start();
 }
 
@@ -45,7 +57,7 @@ void BrowserWithTestWindowTest::SetUp() {
   if (!window_.get())
     window_.reset(new TestBrowserWindow);
 
-  Browser::CreateParams params(profile());
+  Browser::CreateParams params(profile(), host_desktop_type_);
   params.window = window_.get();
   browser_.reset(new Browser(params));
 #if defined(USE_AURA)
diff --git a/chrome/test/base/browser_with_test_window_test.h b/chrome/test/base/browser_with_test_window_test.h
index 76d7b4c..e23c920 100644
--- a/chrome/test/base/browser_with_test_window_test.h
+++ b/chrome/test/base/browser_with_test_window_test.h
@@ -8,6 +8,7 @@
 #include "base/at_exit.h"
 #include "base/message_loop.h"
 #include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/host_desktop.h"
 #include "chrome/test/base/test_browser_window.h"
 #include "chrome/test/base/testing_profile.h"
 #include "content/public/test/test_browser_thread.h"
@@ -57,7 +58,14 @@ class WebContents;
 // for creating the various objects of this class.
 class BrowserWithTestWindowTest : public testing::Test {
  public:
+  // Creates a BrowserWithTestWindowTest for which the initial window will be
+  // created on the native desktop.
   BrowserWithTestWindowTest();
+
+  // Creates a BrowserWithTestWindowTest for which the initial window will be
+  // created on the desktop of type |host_desktop_type|.
+  explicit BrowserWithTestWindowTest(chrome::HostDesktopType host_desktop_type);
+
   virtual ~BrowserWithTestWindowTest();
 
   virtual void SetUp() OVERRIDE;
@@ -136,6 +144,9 @@ class BrowserWithTestWindowTest : public testing::Test {
   ui::ScopedOleInitializer ole_initializer_;
 #endif
 
+  // The desktop to create the initial window on.
+  chrome::HostDesktopType host_desktop_type_;
+
   DISALLOW_COPY_AND_ASSIGN(BrowserWithTestWindowTest);
 };