ChromeOS MD: Fix cannot drag tab onto immersive fullscreen window

chrome/browser/ui/views/tabs/tab_drag_controller.cc

Index: chrome/browser/ui/views/tabs/tab_drag_controller.cc
diff --git a/chrome/browser/ui/views/tabs/tab_drag_controller.cc b/chrome/browser/ui/views/tabs/tab_drag_controller.cc
index 1997b873a2349ff601ee1869a531a63314eee050..5e445a6e3e812b83f49e5202a0d74b6c19fb27a4 100644
--- a/chrome/browser/ui/views/tabs/tab_drag_controller.cc
+++ b/chrome/browser/ui/views/tabs/tab_drag_controller.cc
@@ -111,6 +111,24 @@ gfx::NativeWindow GetModalTransient(gfx::NativeWindow window) {
 }
 #endif
 
+// Get tabstrip bounds from non-client view coordinates where tabstrip should be

[sky, 2017/01/18 16:40:46]

I think you mean, "Returns the bounds of the tabstrip in screen coordinates in
|rect|." I'm a bit confused on how this fails, comments below.

[Qiang(Joe) Xu, 2017/01/20 17:36:25]

changed to GetBoundsForTabStripInBrowserView, so change the comments.

+// laid when revealed, then convert to screen coordinates. Return false if the
+// corresponding browser view doesn't exist.
+bool GetBoundsForTabStripInScreen(TabStrip* tabstrip, gfx::Rect* rect) {
+  if (!tabstrip)
+    return false;

[sky, 2017/01/18 16:40:46]

I think callers should check for this case.

[Qiang(Joe) Xu, 2017/01/20 17:36:25]

caller will make sure it

+  gfx::NativeWindow window = tabstrip->GetWidget()->GetNativeWindow();
+  if (!window)

[sky, 2017/01/18 16:40:46]

Can this case really happen?

[Qiang(Joe) Xu, 2017/01/20 17:36:25]

seems cannot happen. remove it.

+    return false;
+  BrowserView* browser_view =
+      BrowserView::GetBrowserViewForNativeWindow(window);
+  if (!browser_view)

[sky, 2017/01/18 16:40:46]

Same comment here. Can this case really happen?

[Qiang(Joe) Xu, 2017/01/20 17:36:25]

Done.

+    return false;
+  *rect = browser_view->frame()->GetBoundsForTabStrip(tabstrip);

[sky, 2017/01/18 16:40:46]

Why do you need to use GetBoundsForTabStrip rather than the actual bounds?

[Qiang(Joe) Xu, 2017/01/20 17:36:25]

the actual bounds will return (0, 0, 0x0) for this case.

+  aura::Window::ConvertRectToTarget(window, window->GetRootWindow(), rect);
+  return true;
+}
+
 // Returns true if |bounds| contains the y-coordinate |y|. The y-coordinate
 // of |bounds| is adjusted by |vertical_adjustment|.
 bool DoesRectContainVerticalPointExpanded(
@@ -569,6 +587,15 @@ TabDragController::DragBrowserToNewTabStrip(
     return DRAG_BROWSER_RESULT_STOP;
   }
 
+  // If tabstrip is invisible, it is not eligible to determine the tab insertion
+  // position, so show the tabstrip here.
+  gfx::Rect tabstrip_bounds;
+  if (!target_tabstrip->visible() &&
+      GetBoundsForTabStripInScreen(target_tabstrip, &tabstrip_bounds)) {
+    target_tabstrip->SetVisible(true);
+    target_tabstrip->SetBoundsRect(tabstrip_bounds);
+  }
+
 #if defined(USE_AURA)
   // Only Aura windows are gesture consumers.
   ui::GestureRecognizer::Get()->TransferEventsTo(
@@ -856,14 +883,15 @@ TabStrip* TabDragController::GetTabStripForWindow(gfx::NativeWindow window) {
 bool TabDragController::DoesTabStripContain(
     TabStrip* tabstrip,
     const gfx::Point& point_in_screen) const {
-  // Make sure the specified screen point is actually within the bounds of the
-  // specified tabstrip...
-  gfx::Rect tabstrip_bounds = GetViewScreenBounds(tabstrip);
+  // Make sure the specified screen point is within the bounds of the specified
+  // tabstrip where it should be laid when revealed.
+  gfx::Rect tabstrip_bounds;
+  DCHECK(GetBoundsForTabStripInScreen(tabstrip, &tabstrip_bounds));
+
   return point_in_screen.x() < tabstrip_bounds.right() &&
-      point_in_screen.x() >= tabstrip_bounds.x() &&
-      DoesRectContainVerticalPointExpanded(tabstrip_bounds,
-                                           kVerticalDetachMagnetism,
-                                           point_in_screen.y());
+         point_in_screen.x() >= tabstrip_bounds.x() &&
+         DoesRectContainVerticalPointExpanded(
+             tabstrip_bounds, kVerticalDetachMagnetism, point_in_screen.y());
 }
 
 void TabDragController::Attach(TabStrip* attached_tabstrip,