Add detached mode plumbing

ui/accelerated_widget_mac/accelerated_widget_mac.mm

Index: ui/accelerated_widget_mac/accelerated_widget_mac.mm
diff --git a/ui/accelerated_widget_mac/accelerated_widget_mac.mm b/ui/accelerated_widget_mac/accelerated_widget_mac.mm
index fc9269bd20fc1ef5e24e9ec5a773e463ba78d1a4..0c4a1438575c89fe9381c617ebf1223df0150d47 100644
--- a/ui/accelerated_widget_mac/accelerated_widget_mac.mm
+++ b/ui/accelerated_widget_mac/accelerated_widget_mac.mm
@@ -17,6 +17,58 @@
 #include "ui/gfx/geometry/dip_util.h"
 #include "ui/gl/scoped_cgl.h"
 
+@interface DetachedModeWindow : NSWindow {
+  base::WeakPtr<ui::AcceleratedWidgetMac> accelerated_widget_mac_;
+  base::scoped_nsobject<NSWindow> target_window_;
+}
+
+- (id)initWithAcceleratedWidgetMac:
+    (base::WeakPtr<ui::AcceleratedWidgetMac>)accelerated_widget_mac;
+- (void)startForwardingEvents:(NSWindow*)target_window;
+- (void)stopForwardingEvents;
+@end
+
+@implementation DetachedModeWindow : NSWindow
+- (id)initWithAcceleratedWidgetMac:
+    (base::WeakPtr<ui::AcceleratedWidgetMac>)accelerated_widget_mac {
+  if (self = [super
+          initWithContentRect:NSMakeRect(0, 0, 100, 100)
+                    styleMask:NSTitledWindowMask | NSResizableWindowMask |
+                              NSFullSizeContentViewWindowMask
+                      backing:NSBackingStoreBuffered
+                        defer:NO]) {
+    [self setReleasedWhenClosed:NO];
+    accelerated_widget_mac_ = accelerated_widget_mac;
+    return self;
+  }
+  return nil;
+}
+
+- (void)startForwardingEvents:(NSWindow*)target_window {
+  target_window_.reset([target_window retain]);
+}
+
+- (void)stopForwardingEvents {
+  target_window_.reset();
+}
+
+- (void)close {
+  if (accelerated_widget_mac_)
+    accelerated_widget_mac_->DestroyDetachedModeWindow();
+  [super close];
+}
+
+- (void)sendEvent:(NSEvent*)event {
+  // This doesn't actually fix the issue for mouse move. Eh.
+  if (target_window_) 
+    [target_window_ sendEvent:event];
+}
+@end
+
+@interface NSWindowController (HorribleHack)
+- (void)setDetachedVideoLayer:(base::scoped_nsobject<CALayer>)layer;
+@end
+
 @interface CALayer (PrivateAPI)
 - (void)setContentsChanged;
 @end
@@ -45,7 +97,8 @@ AcceleratedWidgetMac* GetHelperFromAcceleratedWidget(
 ////////////////////////////////////////////////////////////////////////////////
 // AcceleratedWidgetMac
 
-AcceleratedWidgetMac::AcceleratedWidgetMac() : view_(nullptr) {
+AcceleratedWidgetMac::AcceleratedWidgetMac()
+    : view_(nullptr), weak_factory_(this) {
   // Disable the fade-in animation as the layers are added.
   ScopedCAActionDisabler disabler;
 
@@ -119,6 +172,8 @@ void AcceleratedWidgetMac::GetVSyncParameters(
 void AcceleratedWidgetMac::GotFrame(
     CAContextID ca_context_id,
     base::ScopedCFTypeRef<IOSurfaceRef> io_surface,
+    bool use_detached_mode,
+    CAContextID detached_ca_context_id,
     const gfx::Size& pixel_size,
     float scale_factor) {
   TRACE_EVENT0("ui", "AcceleratedWidgetMac::GotFrame");
@@ -135,14 +190,22 @@ void AcceleratedWidgetMac::GotFrame(
   last_swap_size_dip_ = gfx::ConvertSizeToDIP(scale_factor, pixel_size);
 
   if (ca_context_id)
-    GotCAContextFrame(ca_context_id, pixel_size, scale_factor);
+    GotCAContextFrame(ca_context_id, use_detached_mode, detached_ca_context_id,
+                      pixel_size, scale_factor);
   else
     GotIOSurfaceFrame(io_surface, pixel_size, scale_factor);
 
+  if (use_detached_mode)
+    EnterDetachedMode();
+  else
+    LeaveDetachedMode();
+
   view_->AcceleratedWidgetSwapCompleted();
 }
 
 void AcceleratedWidgetMac::GotCAContextFrame(CAContextID ca_context_id,
+                                             bool use_detached,
+                                             CAContextID detached_ca_context_id,
                                              const gfx::Size& pixel_size,
                                              float scale_factor) {
   TRACE_EVENT0("ui", "AcceleratedWidgetMac::GotCAContextFrame");
@@ -163,6 +226,14 @@ void AcceleratedWidgetMac::GotCAContextFrame(CAContextID ca_context_id,
     [flipped_layer_ addSublayer:ca_context_layer_];
   }
 
+  if ([detached_ca_context_layer_ contextId] != detached_ca_context_id) {
+    TRACE_EVENT0("ui", "Creating a new CALayerHost");
+    detached_ca_context_layer_.reset([[CALayerHost alloc] init]);
+    [detached_ca_context_layer_ setContextId:detached_ca_context_id];
+    [detached_ca_context_layer_
+        setAutoresizingMask:kCALayerMaxXMargin | kCALayerMaxYMargin];
+  }
+
   // If this replacing a same-type layer, remove it now that the new layer is
   // in the hierarchy.
   if (old_ca_context_layer != ca_context_layer_)
@@ -234,6 +305,8 @@ void AcceleratedWidgetMacGotFrame(
     gfx::AcceleratedWidget widget,
     CAContextID ca_context_id,
     base::ScopedCFTypeRef<IOSurfaceRef> io_surface,
+    bool use_detached,
+    CAContextID detached_ca_context_id,
     const gfx::Size& pixel_size,
     float scale_factor,
     base::TimeTicks* vsync_timebase,
@@ -247,7 +320,8 @@ void AcceleratedWidgetMacGotFrame(
       GetHelperFromAcceleratedWidget(widget);
 
   if (accelerated_widget_mac) {
-    accelerated_widget_mac->GotFrame(ca_context_id, io_surface, pixel_size,
+    accelerated_widget_mac->GotFrame(ca_context_id, io_surface, use_detached,
+                                     detached_ca_context_id, pixel_size,
                                      scale_factor);
     if (vsync_timebase && vsync_interval) {
       accelerated_widget_mac->GetVSyncParameters(vsync_timebase,
@@ -256,4 +330,48 @@ void AcceleratedWidgetMacGotFrame(
   }
 }
 
+NSWindow* AcceleratedWidgetMac::CreateDetachedModeWindow() {
+  DCHECK(!detached_mode_window_);
+
+  detached_mode_window_.reset([[DetachedModeWindow alloc]
+      initWithAcceleratedWidgetMac:weak_factory_.GetWeakPtr()]);
+
+  NSView* view = [detached_mode_window_ contentView];
+  base::scoped_nsobject<CALayer> background_layer([[CALayer alloc] init]);
+  [background_layer setBackgroundColor:CGColorGetConstantColor(kCGColorBlack)];
+  [view setLayer:background_layer];
+  [view setWantsLayer:YES];
+  [background_layer addSublayer:detached_ca_context_layer_];
+  return [detached_mode_window_ retain];
+}
+
+void AcceleratedWidgetMac::EnterDetachedMode() {
+  if (!detached_mode_window_ || in_detached_mode_)
+    return;
+  in_detached_mode_ = true;
+  NSWindow* view_window = [view_->AcceleratedWidgetGetNSView() window];
+  [detached_mode_window_ setFrame:[view_window frame] display:YES];
+  [detached_mode_window_
+      setStyleMask:[detached_mode_window_ styleMask] | NSFullScreenWindowMask];
+  // FIXME: This causes events to not be forwarded to the correct window.
+  [detached_mode_window_ orderWindow:NSWindowAbove
+                          relativeTo:[view_window windowNumber]];
+  [detached_mode_window_ startForwardingEvents:view_window];
+}
+
+void AcceleratedWidgetMac::LeaveDetachedMode() {
+  if (!detached_mode_window_ || !in_detached_mode_)
+    return;
+  in_detached_mode_ = false;
+  NSWindow* view_window = [view_->AcceleratedWidgetGetNSView() window];
+  [detached_mode_window_ orderWindow:NSWindowBelow
+                          relativeTo:[view_window windowNumber]];
+  [detached_mode_window_ stopForwardingEvents];
+}
+
+void AcceleratedWidgetMac::DestroyDetachedModeWindow() {
+  LeaveDetachedMode();
+  detached_mode_window_.reset();
+}
+
 }  // namespace ui