Add always-on-top property to app windows

The chrome.app.window API has been extended to include:
- A new alwaysOnTop option for the create() function.
- An AppWindow.isAlwaysOnTop() function to query the state of this
property.
- An AppWindow.setAlwaysOnTop() function to change this property after
creation of the window.

Changes involving native app windows:
- Added apps::NativeAppWindow::SetAlwaysOnTop().
- Implemented IsAlwaysOnTop(), a function inherited from ui::BaseWindow
but was left unimplemented for native app windows.

Changes involving views:
- Added IsAlwaysOnTop(). SetAlwaysOnTop() already existed.

BUG=171597
TEST=browser_tests (PlatformAppBrowserTest.WindowsApiAlwaysOnTop).
Test manually by creating an app that enables the alwaysOnTop option
on window creation and changes the property after creation.
Test Windows, Mac, ChromeOS and Linux.

Review URL: https://codereview.chromium.org/26427002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228160 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 7 insertions, 1 deletions

diff --git a/apps/app_window_contents.cc b/apps/app_window_contents.cc
index 56ae403..ccafd05 100644
--- a/apps/app_window_contents.cc
+++ b/apps/app_window_contents.cc
@@ -92,6 +92,7 @@ void AppWindowContents::NativeWindowChanged(
                          native_app_window->IsFullscreenOrPending());
   dictionary->SetBoolean("minimized", native_app_window->IsMinimized());
   dictionary->SetBoolean("maximized", native_app_window->IsMaximized());
+  dictionary->SetBoolean("alwaysOnTop", native_app_window->IsAlwaysOnTop());
 
   content::RenderViewHost* rvh = web_contents_->GetRenderViewHost();
   rvh->Send(new ExtensionMsg_MessageInvoke(rvh->GetRoutingID(),
diff --git a/apps/shell_window.cc b/apps/shell_window.cc
index 691bff8..e722f4a 100644
--- a/apps/shell_window.cc
+++ b/apps/shell_window.cc
@@ -65,7 +65,8 @@ ShellWindow::CreateParams::CreateParams()
     state(ui::SHOW_STATE_DEFAULT),
     hidden(false),
     resizable(true),
-    focused(true) {}
+    focused(true),
+    always_on_top(false) {}
 
 ShellWindow::CreateParams::~CreateParams() {}
 
diff --git a/apps/shell_window.h b/apps/shell_window.h
index 3d42da7..aee0cc5 100644
--- a/apps/shell_window.h
+++ b/apps/shell_window.h
@@ -123,6 +123,10 @@ class ShellWindow : public content::NotificationObserver,
 
     // If true, the window will be focused on creation. Defaults to true.
     bool focused;
+
+    // If true, the window will stay on top of other windows that are not
+    // configured to be always on top. Defaults to false.
+    bool always_on_top;
   };
 
   class Delegate {