Extract MonitorInfoProvider from WindowSizer.

ui/gfx/screen_mac.mm

Index: ui/gfx/screen_mac.mm
diff --git a/ui/gfx/screen_mac.mm b/ui/gfx/screen_mac.mm
index 6bf0992896bccceb7295458bf39e3e42fe29416b..a3b7306d593f817f8b1976e28f0fbd77721866f0 100644
--- a/ui/gfx/screen_mac.mm
+++ b/ui/gfx/screen_mac.mm
@@ -7,6 +7,39 @@
 #import <ApplicationServices/ApplicationServices.h>
 #import <Cocoa/Cocoa.h>
 
+namespace {
+
+gfx::Rect ConvertCoordinateSystem(NSRect ns_rect) {
+  // Primary monitor is defined as the monitor with the menubar,
+  // which is always at index 0.
+  NSScreen* primary_screen = [[NSScreen screens] objectAtIndex:0];
+  float primary_screen_height = [primary_screen frame].size.height;
+  gfx::Rect rect(NSRectToCGRect(ns_rect));
+  rect.set_y(primary_screen_height - rect.y() - rect.height());
+  return rect;
+}
+
+NSScreen* GetMatchingScreen(const gfx::Rect& match_rect) {
+  // Default to the monitor with the current keyboard focus, in case
+  // |match_rect| is not on any screen at all.
+  NSScreen* max_screen = [NSScreen mainScreen];
+  int max_area = 0;
+
+  for (NSScreen* screen in [NSScreen screens]) {
+    gfx::Rect monitor_area = ConvertCoordinateSystem([screen frame]);
+    gfx::Rect intersection = monitor_area.Intersect(match_rect);
+    int area = intersection.width() * intersection.height();
+    if (area > max_area) {
+      max_area = area;
+      max_screen = screen;
+    }
+  }
+
+  return max_screen;
+}
+
+}  // namespace
+
 namespace gfx {
 
 // static
@@ -19,6 +52,35 @@ gfx::Point Screen::GetCursorScreenPoint() {
 }
 
 // static
+gfx::Rect Screen::GetPrimaryMonitorWorkArea() {
+  // Primary monitor is defined as the monitor with the menubar,
+  // which is always at index 0.
+  NSScreen* primary = [[NSScreen screens] objectAtIndex:0];
+  NSRect frame = [primary frame];
+  NSRect visible_frame = [primary visibleFrame];
+
+  // Convert coordinate systems.
+  gfx::Rect rect = gfx::Rect(NSRectToCGRect(visible_frame));
+  rect.set_y(frame.size.height - visible_frame.origin.y -
+             visible_frame.size.height);
+  return rect;
+}
+
+// static
+gfx::Rect Screen::GetPrimaryMonitorBounds() {
+  // Primary monitor is defined as the monitor with the menubar,
+  // which is always at index 0.
+  NSScreen* primary = [[NSScreen screens] objectAtIndex:0];
+  return gfx::Rect(NSRectToCGRect([primary frame]));
+}
+
+// static
+gfx::Rect Screen::GetMonitorWorkAreaMatching(const gfx::Rect& match_rect) {
+  NSScreen* match_screen = GetMatchingScreen(match_rect);
+  return ConvertCoordinateSystem([match_screen visibleFrame]);
+}
+
+// static
 gfx::Size Screen::GetPrimaryMonitorSize() {
   CGDirectDisplayID main_display = CGMainDisplayID();
   return gfx::Size(CGDisplayPixelsWide(main_display),