cros: ensure minimum window visibility for setting arc window bounds

changes:
Applying minimum window visibility (25DIPs) when setting arc window
bounds.

Bug: 806094
Test: tested on device
Change-Id: Ia89080bfc4a984395dea327e2ed3ab6229c43467
Reviewed-on: https://chromium-review.googlesource.com/899961Reviewed-by: David Reveman <reveman@chromium.org>
Commit-Queue: Qiang Xu <warx@google.com>
Cr-Commit-Position: refs/heads/master@{#536879}

components/exo/shell_surface_base.cc

@@ -12,7 +12,9 @@
 #include "ash/public/cpp/window_properties.h"
 #include "ash/public/cpp/window_state_type.h"
 #include "ash/public/interfaces/window_pin_type.mojom.h"
+#include "ash/screen_util.h"
 #include "ash/wm/drag_window_resizer.h"
+#include "ash/wm/window_positioning_utils.h"
 #include "ash/wm/window_resizer.h"
 #include "ash/wm/window_state.h"
 #include "ash/wm/window_state_delegate.h"
@@ -1219,6 +1221,14 @@ void ShellSurfaceBase::UpdateWidgetBounds() {
           visible_bounds);
   new_widget_bounds.set_origin(GetWidgetOrigin());
 
+  // Adjust window bounds to ensure minimum window visibility.
+  aura::Window* window = widget_->GetNativeWindow();
+  wm::ConvertRectFromScreen(window->GetRootWindow(), &new_widget_bounds);
+  gfx::Rect display_area = ash::screen_util::GetDisplayBoundsInParent(window);
+  ash::wm::AdjustBoundsToEnsureMinimumWindowVisibility(display_area,
+                                                       &new_widget_bounds);
+  wm::ConvertRectToScreen(window->GetRootWindow(), &new_widget_bounds);
+
   // Set |ignore_window_bounds_changes_| as this change to window bounds
   // should not result in a configure request.
   DCHECK(!ignore_window_bounds_changes_);

components/exo/shell_surface_unittest.cc

@@ -9,6 +9,7 @@
 #include "ash/shell.h"
 #include "ash/shell_port.h"
 #include "ash/shell_test_api.h"
+#include "ash/wm/window_positioning_utils.h"
 #include "ash/wm/window_state.h"
 #include "ash/wm/wm_event.h"
 #include "ash/wm/workspace/workspace_window_resizer.h"
@@ -476,5 +477,30 @@ TEST_F(ShellSurfaceTest, ToggleFullscreen) {
             shell_surface->GetWidget()->GetWindowBoundsInScreen().width());
 }
 
+TEST_F(ShellSurfaceTest, EnsureMinimumVisibility) {
+  gfx::Size buffer_size(64, 64);
+  std::unique_ptr<Buffer> buffer(
+      new Buffer(exo_test_helper()->CreateGpuMemoryBuffer(buffer_size)));
+  std::unique_ptr<Surface> surface(new Surface);
+  std::unique_ptr<ShellSurface> shell_surface(new ShellSurface(surface.get()));
+
+  gfx::Size content_size(100, 100);
+  gfx::Rect original_bounds(gfx::Point(16, 16), content_size);
+  shell_surface->SetGeometry(original_bounds);
+  surface->Attach(buffer.get());
+  surface->Commit();
+
+  display::Display display = display::Screen::GetScreen()->GetPrimaryDisplay();
+  int display_width = display.bounds().width();
+  gfx::Rect new_bounds(gfx::Point(display_width + 100, 10), content_size);
+  shell_surface->GetWidget()->SetBounds(new_bounds);
+  surface->Commit();
+
+  const gfx::Rect expected_bounds(display_width - ash::wm::kMinimumOnScreenArea,
+                                  10, 100, 100);
+  EXPECT_EQ(expected_bounds,
+            shell_surface->GetWidget()->GetWindowBoundsInScreen());
+}
+
 }  // namespace
 }  // namespace exo