mac: Fix screen capture for whole-desktop capture.

webrtc/modules/desktop_capture/screen_capturer_mac.mm

Index: webrtc/modules/desktop_capture/screen_capturer_mac.mm
diff --git a/webrtc/modules/desktop_capture/screen_capturer_mac.mm b/webrtc/modules/desktop_capture/screen_capturer_mac.mm
index b1d7c9048e91d3c482fc249eaa5db701b61279cc..aed7e25e8d87933418878cdeeffd4499cfd93029 100644
--- a/webrtc/modules/desktop_capture/screen_capturer_mac.mm
+++ b/webrtc/modules/desktop_capture/screen_capturer_mac.mm
@@ -304,7 +304,9 @@ class ScreenCapturerMac : public DesktopCapturer {
   bool RegisterRefreshAndMoveHandlers();
   void UnregisterRefreshAndMoveHandlers();
 
-  void ScreenRefresh(CGRectCount count, const CGRect *rect_array);
+  void ScreenRefresh(CGRectCount count,
+                     const CGRect *rect_array,
+                     DesktopVector display_origin);
   void ReleaseBuffers();
 
   std::unique_ptr<DesktopFrame> CreateFrame();
@@ -938,6 +940,8 @@ bool ScreenCapturerMac::RegisterRefreshAndMoveHandlers() {
     DisplayStreamManager* manager = display_stream_manager_;
     int unique_id = manager->GetUniqueId();
     CGDirectDisplayID display_id = config.id;
+    DesktopVector display_origin = config.pixel_bounds.top_left();
+
     CGDisplayStreamFrameAvailableHandler handler =
         ^(CGDisplayStreamFrameStatus status, uint64_t display_time,
           IOSurfaceRef frame_surface, CGDisplayStreamUpdateRef updateRef) {
@@ -959,7 +963,7 @@ bool ScreenCapturerMac::RegisterRefreshAndMoveHandlers() {
           if (count != 0) {
             // According to CGDisplayStream.h, it's safe to call
             // CGDisplayStreamStop() from within the callback.
-            ScreenRefresh(count, rects);
+            ScreenRefresh(count, rects, display_origin);
           }
         };
     CGDisplayStreamRef display_stream = CGDisplayStreamCreate(
@@ -985,16 +989,28 @@ void ScreenCapturerMac::UnregisterRefreshAndMoveHandlers() {
 }
 
 void ScreenCapturerMac::ScreenRefresh(CGRectCount count,
-                                      const CGRect* rect_array) {
+                                      const CGRect* rect_array,
+                                      DesktopVector display_origin) {
   if (screen_pixel_bounds_.is_empty())
     ScreenConfigurationChanged();
 
+  // The refresh rects are in display coordinates. We want to translate to
+  // framebuffer coordinates. If a specific display is being captured, then no
+  // change is necessary. If all displays are being captured, then we want to
+  // translate by the origin of the display.
+  DesktopVector translate_vector;
+  if (!current_display_)
+    translate_vector = display_origin;
+
   DesktopRegion region;
   for (CGRectCount i = 0; i < count; ++i) {
     // All rects are already in physical pixel coordinates.
     DesktopRect rect = DesktopRect::MakeXYWH(
         rect_array[i].origin.x, rect_array[i].origin.y,
         rect_array[i].size.width, rect_array[i].size.height);
+
+    rect.Translate(translate_vector);
+
     region.AddRect(rect);
   }