Disable accelerated compositing to fix everything.

app/atom_main_delegate.cc

@@ -46,9 +46,14 @@ void AtomMainDelegate::PreSandboxStartup() {
 #endif
   InitializeResourceBundle();
 
-  // Disable renderer sandbox for most of node's functions.
   CommandLine* command_line = CommandLine::ForCurrentProcess();
+
+  // Disable renderer sandbox for most of node's functions.
   command_line->AppendSwitch(switches::kNoSandbox);
+
+  // Disable accelerated compositing since it caused a lot of troubles (black
+  // devtools, screen flashes) and needed lots of effort to make it right.
+  command_line->AppendSwitch(switches::kDisableAcceleratedCompositing);
 }
 
 void AtomMainDelegate::InitializeResourceBundle() {

browser/ui/atom_event_processing_window.h

@@ -7,12 +7,10 @@
 
 #import <Cocoa/Cocoa.h>
 
-#import "ui/base/cocoa/underlay_opengl_hosting_window.h"
-
 // Override NSWindow to access unhandled keyboard events (for command
 // processing); subclassing NSWindow is the only method to do
 // this.
-@interface AtomEventProcessingWindow : UnderlayOpenGLHostingWindow {
+@interface AtomEventProcessingWindow : NSWindow {
  @private
   BOOL redispatchingEvent_;
   BOOL eventHandled_;