Edge extension should take rotation/overscan into account

Bug: 843354, b/141898654
Test: covered by unittest
Change-Id: Ib92013f3e0721c054c94981d93a8b2167076fa8c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1911100Reviewed-by: Malay Keshav <malaykeshav@chromium.org>
Commit-Queue: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#715089}

ash/screen_util.cc

@@ -104,30 +104,26 @@ gfx::Rect GetDisplayBoundsWithShelf(aura::Window* window) {
 
 gfx::Rect SnapBoundsToDisplayEdge(const gfx::Rect& bounds,
                                   const aura::Window* window) {
-  const aura::WindowTreeHost* host = window->GetHost();
-  if (!host)
-    return bounds;
+  display::Display display =
+      display::Screen::GetScreen()->GetDisplayNearestWindow(
+          const_cast<aura::Window*>(window));
 
-  const float dsf = host->device_scale_factor();
-  const gfx::Rect display_bounds_in_pixel = host->GetBoundsInPixels();
-  const gfx::Rect display_bounds_in_dip = window->GetRootWindow()->bounds();
-  const gfx::Rect bounds_in_pixel = gfx::ScaleToEnclosedRect(bounds, dsf);
+  const float dsf = display.device_scale_factor();
+  const gfx::Size display_size_in_pixel = display.GetSizeInPixel();
+  const gfx::Size scaled_size_in_pixel =
+      gfx::ScaleToFlooredSize(display.size(), dsf);
 
   // Adjusts |bounds| such that the scaled enclosed bounds are atleast as big as
   // the scaled enclosing unadjusted bounds.
   gfx::Rect snapped_bounds = bounds;
-  if ((display_bounds_in_dip.width() == bounds.width() &&
-       bounds_in_pixel.width() != display_bounds_in_pixel.width()) ||
-      (bounds.right() == display_bounds_in_dip.width() &&
-       bounds_in_pixel.right() != display_bounds_in_pixel.width())) {
+  if (scaled_size_in_pixel.width() < display_size_in_pixel.width() &&
+      display.bounds().right() == bounds.right()) {
     snapped_bounds.Inset(0, 0, -1, 0);
     DCHECK_GE(gfx::ScaleToEnclosedRect(snapped_bounds, dsf).right(),
               gfx::ScaleToEnclosingRect(bounds, dsf).right());
   }
-  if ((display_bounds_in_dip.height() == bounds.height() &&
-       bounds_in_pixel.height() != display_bounds_in_pixel.height()) ||
-      (bounds.bottom() == display_bounds_in_dip.height() &&
-       bounds_in_pixel.bottom() != display_bounds_in_pixel.height())) {
+  if (scaled_size_in_pixel.height() < display_size_in_pixel.height() &&
+      display.bounds().bottom() == bounds.bottom()) {
     snapped_bounds.Inset(0, 0, 0, -1);
     DCHECK_GE(gfx::ScaleToEnclosedRect(snapped_bounds, dsf).bottom(),
               gfx::ScaleToEnclosingRect(bounds, dsf).bottom());

ash/screen_util_unittest.cc

@@ -223,6 +223,13 @@ TEST_F(ScreenUtilTest, SnapBoundsToDisplayEdge) {
   bounds = gfx::Rect(0, 552, 800, 48);
   snapped_bounds = screen_util::SnapBoundsToDisplayEdge(bounds, window);
   EXPECT_EQ(snapped_bounds, gfx::Rect(0, 552, 800, 48));
+
+  UpdateDisplay("2400x1800*1.8/r");
+  EXPECT_EQ(gfx::Size(1000, 1333),
+            display::Screen::GetScreen()->GetPrimaryDisplay().size());
+  bounds = gfx::Rect(950, 0, 50, 1333);
+  snapped_bounds = screen_util::SnapBoundsToDisplayEdge(bounds, window);
+  EXPECT_EQ(snapped_bounds, gfx::Rect(950, 0, 50, 1334));
 }
 
 // Tests that making a window fullscreen while the Docked Magnifier is enabled