Fixed wrong cursor position when dragging window by tab detach

fix brave/brave-browser#44393

This is f/u fix as #27909
is reverted in cr135.

We adjusted window offset while dragging in vertical tab mode
because TabDragController refers widget from TabDraggingContext but
that widget is vertical tab widget not browser window widget.
However, upstream refactored TabDragController so we need to adjust
based on latest code again.

Upstream changes - https://chromium-review.googlesource.com/c/chromium/src/+/6160815
Our previous offset adjust - #27909

Enabled tab detach browser test again(VerticalTabStripDragAndDropBrowserTest.DragTabToDetach)
to check mouse cursor is located over the dragged tab properly during
the dragging. But not sure it works well on CI.

Author: simonhong

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

@@ -119,6 +119,23 @@ gfx::Point TabDragController::GetAttachedDragPoint(
   return {x, y};
 }
 
+gfx::Vector2d TabDragController::CalculateWindowDragOffset() {
+  gfx::Vector2d offset = TabDragControllerChromium::CalculateWindowDragOffset();
+  if (!is_showing_vertical_tabs_) {
+    return offset;
+  }
+
+  // Re-calculate offset as above result is based on vertical tab widget.
+  // Convert it based on browser window widget(top level widget).
+  gfx::Point new_offset(offset.x(), offset.y());
+  views::View::ConvertPointFromWidget(attached_context_, &new_offset);
+  views::View::ConvertPointToScreen(attached_context_, &new_offset);
+  views::View::ConvertPointFromScreen(
+      attached_context_->GetWidget()->GetTopLevelWidget()->GetRootView(),
+      &new_offset);
+  return new_offset.OffsetFromOrigin();
+}
+
 void TabDragController::MoveAttached(const gfx::Point& point_in_screen,
                                      bool just_attached) {
   TabDragControllerChromium::MoveAttached(point_in_screen, just_attached);

browser/ui/views/tabs/dragging/tab_drag_controller.h

@@ -34,6 +34,7 @@ class TabDragController : public TabDragControllerChromium {
   void MoveAttached(const gfx::Point& point_in_screen,
                     bool just_attached) override;
   views::Widget* GetAttachedBrowserWidget() override;
+  gfx::Vector2d CalculateWindowDragOffset() override;
 
   Liveness GetLocalProcessWindow(const gfx::Point& screen_point,
                                  bool exclude_dragged_view,

browser/ui/views/tabs/vertical_tab_strip_browsertest.cc

@@ -956,7 +956,11 @@ IN_PROC_BROWSER_TEST_F(VerticalTabStripDragAndDropBrowserTest,
 // TODO(sko) On Linux test environment, the test doesn't work well
 // TODO(sko) On Windows CI, SendMouse() doesn't work.
 // TODO(sko) As of Dec, 2023 this test is flaky on Mac CI.
+#if BUILDFLAG(IS_WIN)
+#define MAYBE_DragTabToDetach DragTabToDetach
+#else
 #define MAYBE_DragTabToDetach DISABLED_DragTabToDetach
+#endif
 
 IN_PROC_BROWSER_TEST_F(VerticalTabStripDragAndDropBrowserTest,
                        MAYBE_DragTabToDetach) {
@@ -979,8 +983,16 @@ IN_PROC_BROWSER_TEST_F(VerticalTabStripDragAndDropBrowserTest,
                           std::ranges::count_if(*browser_list, [&](Browser* b) {
                             return b->profile() == browser()->profile();
                           }));
-                ReleaseMouse();
                 auto* new_browser = browser_list->GetLastActive();
+                auto* browser_view =
+                    BrowserView::GetBrowserViewForBrowser(new_browser);
+                auto* tab = browser_view->tabstrip()->tab_at(0);
+                ASSERT_TRUE(tab);
+                // During the tab detaching, mouse should be over the dragged
+                // tab.
+                EXPECT_TRUE(tab->IsMouseHovered());
+                EXPECT_TRUE(tab->dragging());
+                ReleaseMouse();
                 new_browser->window()->Close();
               }));
 }

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

@@ -37,9 +37,11 @@
 // StackAtTop() should be called vertical tab widget's top level widget.
 // This also works in horizontal tab mode because it's already top level window.
 #define StackAtTop GetTopLevelWidget()->StackAtTop
+#define GetWindowBoundsInScreen GetTopLevelWidget()->GetWindowBoundsInScreen
 
 #include "src/chrome/browser/ui/views/tabs/dragging/tab_drag_controller.cc"
 
+#undef GetWindowBoundsInScreen
 #undef StackAtTop
 #undef GetHorizontalDragThreshold
 #undef GetBrowserViewForNativeWindow

chromium_src/chrome/browser/ui/views/tabs/dragging/tab_drag_controller.h

@@ -29,6 +29,13 @@ using TabDragControllerBrave = TabDragController;
     return {};                        \
   }                                   \
   virtual views::Widget* GetAttachedBrowserWidget
+
+#define CalculateWindowDragOffset      \
+  CalculateWindowDragOffset_Unused() { \
+    return {};                         \
+  }                                    \
+  virtual gfx::Vector2d CalculateWindowDragOffset
+
 #define GetLocalProcessWindow virtual GetLocalProcessWindow
 #define DetachAndAttachToNewContext virtual DetachAndAttachToNewContext
 #define ContinueDragging virtual ContinueDragging
@@ -38,6 +45,7 @@ using TabDragControllerBrave = TabDragController;
 #undef ContinueDragging
 #undef DetachAndAttachToNewContext
 #undef GetLocalProcessWindow
+#undef CalculateWindowDragOffset
 #undef GetAttachedBrowserWidget
 #undef TabDragController
 #undef InitDragData