MacViews: Implement NativeWidgetMac::GetWorkAreaBoundsInScreen()

It's needed to position some menus, among other things.

It's just [[window screen] visibleFrame], but it should have some test
coverage too.

BUG=522794, 454698

Review URL: https://codereview.chromium.org/1306763002

Cr-Commit-Position: refs/heads/master@{#344709}

2 files changed, 22 insertions, 2 deletions

diff --git a/ui/views/widget/native_widget_mac.mm b/ui/views/widget/native_widget_mac.mm
index 0139943..4f92b40 100644
--- a/ui/views/widget/native_widget_mac.mm
+++ b/ui/views/widget/native_widget_mac.mm
@@ -515,8 +515,7 @@ void NativeWidgetMac::ClearNativeFocus() {
 }
 
 gfx::Rect NativeWidgetMac::GetWorkAreaBoundsInScreen() const {
-  NOTIMPLEMENTED();
-  return gfx::Rect();
+  return gfx::ScreenRectFromNSRect([[GetNativeWindow() screen] visibleFrame]);
 }
 
 Widget::MoveLoopResult NativeWidgetMac::RunMoveLoop(
diff --git a/ui/views/widget/native_widget_mac_unittest.mm b/ui/views/widget/native_widget_mac_unittest.mm
index f97fcb0..bc6c65c 100644
--- a/ui/views/widget/native_widget_mac_unittest.mm
+++ b/ui/views/widget/native_widget_mac_unittest.mm
@@ -962,6 +962,27 @@ TEST_F(NativeWidgetMacTest, InvalidateShadow) {
   widget->CloseNow();
 }
 
+// Test the expected result of GetWorkAreaBoundsInScreen().
+TEST_F(NativeWidgetMacTest, GetWorkAreaBoundsInScreen) {
+  Widget widget;
+  Widget::InitParams params = CreateParams(Widget::InitParams::TYPE_POPUP);
+  params.ownership = Widget::InitParams::WIDGET_OWNS_NATIVE_WIDGET;
+
+  // This is relative to the top-left of the primary screen, so unless the bot's
+  // display is smaller than 400x300, the window will be wholly contained there.
+  params.bounds = gfx::Rect(100, 100, 300, 200);
+  widget.Init(params);
+  widget.Show();
+  NSRect expected = [[[NSScreen screens] objectAtIndex:0] visibleFrame];
+  NSRect actual = gfx::ScreenRectToNSRect(widget.GetWorkAreaBoundsInScreen());
+  EXPECT_FALSE(NSIsEmptyRect(actual));
+  EXPECT_NSEQ(expected, actual);
+
+  [widget.GetNativeWindow() close];
+  actual = gfx::ScreenRectToNSRect(widget.GetWorkAreaBoundsInScreen());
+  EXPECT_TRUE(NSIsEmptyRect(actual));
+}
+
 }  // namespace test
 }  // namespace views