Cocoa: Support constrained windows for platform apps

chrome/browser/ui/cocoa/extensions/shell_window_cocoa.mm

Index: chrome/browser/ui/cocoa/extensions/shell_window_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/extensions/shell_window_cocoa.mm b/chrome/browser/ui/cocoa/extensions/shell_window_cocoa.mm
index 828d4adf7ad538c3e176f701ec34dcc13b3a0b94..82df758c8e236bfd724402ecc4ecda629d12c618 100644
--- a/chrome/browser/ui/cocoa/extensions/shell_window_cocoa.mm
+++ b/chrome/browser/ui/cocoa/extensions/shell_window_cocoa.mm
@@ -9,6 +9,7 @@
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/cocoa/browser_window_utils.h"
 #include "chrome/browser/ui/cocoa/extensions/extension_view_mac.h"
+#include "chrome/browser/ui/tab_contents/tab_contents.h"
 #include "chrome/common/extensions/extension.h"
 #include "content/public/browser/render_widget_host_view.h"
 #include "content/public/browser/web_contents.h"
@@ -48,6 +49,29 @@
     shellWindow_->WindowDidResignKey();
 }
 
+- (void)gtm_systemRequestsVisibilityForView:(NSView*)view {
+  [[self window] makeKeyAndOrderFront:self];
+}
+
+- (void)attachConstrainedWindow:(ConstrainedWindowMac*)window {
+  if (!sheetController_.get()) {
+    sheetController_.reset([[GTMWindowSheetController alloc]
+        initWithWindow:[self window]
+              delegate:self]);
+  }
+
+  NSView* tabContentsView =
+      [window->owner()->web_contents()->GetNativeView() superview];
+  window->delegate()->RunSheet(sheetController_, tabContentsView);
+}
+
+- (void)removeConstrainedWindow:(ConstrainedWindowMac*)window {
+}
+
+- (BOOL)canAttachConstrainedWindow {
+  return YES;
+}
+
 @end
 
 @interface ShellNSWindow : UnderlayOpenGLHostingWindow