Revert of Use a single CGLContextObj to draw and update the IOSurface

content/browser/compositor/io_surface_layer_mac.mm

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/compositor/io_surface_layer_mac.h"
 
 #include <CoreFoundation/CoreFoundation.h>
 #include <OpenGL/CGLIOSurface.h>
 #include <OpenGL/CGLRenderers.h>
 #include <OpenGL/gl.h>
@@ skipping 156 matching lines @@
 // IOSurfaceLayer
 
 @implementation IOSurfaceLayer
 
 - (id)initWithClient:(content::IOSurfaceLayerClient*)client
      withScaleFactor:(float)scale_factor {
   if (self = [super init]) {
     helper_.reset(new content::IOSurfaceLayerHelper(client, self));
 
     iosurface_ = content::IOSurfaceTexture::Create();
-    if (!iosurface_.get()) {
+    context_ = content::IOSurfaceContext::Get(
+        content::IOSurfaceContext::kCALayerContext);
+    if (!iosurface_.get() || !context_.get()) {
       LOG(ERROR) << "Failed create CompositingIOSurface or context";
       [self resetClient];
       [self release];
       return nil;
     }
 
     [self setBackgroundColor:CGColorGetConstantColor(kCGColorWhite)];
     [self setAnchorPoint:CGPointMake(0, 0)];
     // Setting contents gravity is necessary to prevent the layer from being
     // scaled during dyanmic resizes (especially with devtools open).
@@ skipping 10 matching lines @@
   [super dealloc];
 }
 
 - (bool)gotFrameWithIOSurface:(IOSurfaceID)io_surface_id
                 withPixelSize:(gfx::Size)pixel_size
               withScaleFactor:(float)scale_factor {
   return iosurface_->SetIOSurface(io_surface_id, pixel_size);
 }
 
 - (void)poisonContextAndSharegroup {
-  iosurface_->context()->PoisonContextAndSharegroup();
+  context_->PoisonContextAndSharegroup();
 }
 
 - (bool)hasBeenPoisoned {
-  return iosurface_->context()->HasBeenPoisoned();
+  return context_->HasBeenPoisoned();
 }
 
 - (float)scaleFactor {
   if ([self respondsToSelector:(@selector(contentsScale))])
     return [self contentsScale];
   return 1;
 }
 
 - (int)rendererID {
   GLint current_renderer_id = -1;
-  if (CGLGetParameter(iosurface_->context()->cgl_context(),
+  if (CGLGetParameter(context_->cgl_context(),
                       kCGLCPCurrentRendererID,
                       &current_renderer_id) == kCGLNoError) {
     return current_renderer_id & kCGLRendererIDMatchingMask;
   }
   return -1;
 }
 
 - (void)resetClient {
   helper_.reset();
 }
@@ skipping 14 matching lines @@
   helper_->BeginPumpingFrames();
 }
 
 - (void)endPumpingFrames {
   helper_->EndPumpingFrames();
 }
 
 // The remaining methods implement the CAOpenGLLayer interface.
 
 - (CGLPixelFormatObj)copyCGLPixelFormatForDisplayMask:(uint32_t)mask {
-  return CGLRetainPixelFormat(
-      CGLGetPixelFormat(iosurface_->context()->cgl_context()));
+  if (!context_.get())
+    return [super copyCGLPixelFormatForDisplayMask:mask];
+  return CGLRetainPixelFormat(CGLGetPixelFormat(context_->cgl_context()));
 }
 
 - (CGLContextObj)copyCGLContextForPixelFormat:(CGLPixelFormatObj)pixelFormat {
-  return CGLRetainContext(iosurface_->context()->cgl_context());
+  if (!context_.get())
+    return [super copyCGLContextForPixelFormat:pixelFormat];
+  return CGLRetainContext(context_->cgl_context());
 }
 
 - (void)setNeedsDisplay {
   if (helper_)
     helper_->SetNeedsDisplay();
   [super setNeedsDisplay];
 }
 
 - (BOOL)canDrawInCGLContext:(CGLContextObj)glContext
                 pixelFormat:(CGLPixelFormatObj)pixelFormat
@@ skipping 14 matching lines @@
   if (helper_)
     helper_->DidDraw(draw_succeeded);
 
   [super drawInCGLContext:glContext
               pixelFormat:pixelFormat
              forLayerTime:timeInterval
               displayTime:timeStamp];
 }
 
 @end