Ensure that CAOpenGLLayer uses the dGPU when appropriate.

content/browser/renderer_host/compositing_iosurface_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/renderer_host/compositing_iosurface_layer_mac.h"
 
 #include <CoreFoundation/CoreFoundation.h>
 #include <OpenGL/gl.h>
 
 #include "base/mac/sdk_forward_declarations.h"
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/browser/renderer_host/render_widget_host_view_mac.h"
 #include "content/browser/renderer_host/compositing_iosurface_context_mac.h"
 #include "content/browser/renderer_host/compositing_iosurface_mac.h"
 #include "ui/base/cocoa/animation_utils.h"
 #include "ui/gfx/size_conversions.h"
+#include "ui/gl/gpu_switching_manager.h"
 
 @implementation CompositingIOSurfaceLayer
 
 @synthesize context = context_;
 
 - (id)initWithRenderWidgetHostViewMac:(content::RenderWidgetHostViewMac*)r {
   if (self = [super init]) {
     renderWidgetHostView_ = r;
 
     ScopedCAActionDisabler disabler;
@@ skipping 28 matching lines @@
 }
 
 - (void)disableCompositing{
   ScopedCAActionDisabler disabler;
   [self removeFromSuperlayer];
   renderWidgetHostView_ = nil;
 }
 
 // The remaining methods implement the CAOpenGLLayer interface.
 
+- (CGLPixelFormatObj)copyCGLPixelFormatForDisplayMask:(uint32_t)mask {
+  std::vector<CGLPixelFormatAttribute> attribs;
+  attribs.push_back(kCGLPFADepthSize);
+  attribs.push_back(static_cast<CGLPixelFormatAttribute>(0));
+  if (ui::GpuSwitchingManager::GetInstance()->SupportsDualGpus()) {
+    attribs.push_back(kCGLPFAAllowOfflineRenderers);
+    attribs.push_back(static_cast<CGLPixelFormatAttribute>(1));
+  }
+  attribs.push_back(static_cast<CGLPixelFormatAttribute>(0));
+
+  GLint number_virtual_screens = 0;
+  CGLPixelFormatObj pixel_format = NULL;
+  CGLError error = CGLChoosePixelFormat(
+      &attribs.front(), &pixel_format, &number_virtual_screens);
+  if (error != kCGLNoError) {
+    LOG(ERROR) << "Failed to create pixel format for layer.";
+    return nil;
+  }
+  return pixel_format;
+}
+
+- (void)releaseCGLPixelFormat:(CGLPixelFormatObj)pixelFormat {
+  CGLReleasePixelFormat(pixelFormat);
+}
+
 - (CGLContextObj)copyCGLContextForPixelFormat:(CGLPixelFormatObj)pixelFormat {
-  if (!renderWidgetHostView_)
+  if (!renderWidgetHostView_) {
+    LOG(ERROR) << "Cannot create layer context because there is no host.";
     return nil;
+  }
 
   context_ = renderWidgetHostView_->compositing_iosurface_context_;
-  if (!context_)
+  if (!context_) {
+    LOG(ERROR) << "Cannot create layer context because host has no context.";
     return nil;
+  }
 
   return context_->cgl_context();
 }
 
 - (void)releaseCGLContext:(CGLContextObj)glContext {
   if (!context_.get())
     return;
 
   DCHECK(glContext == context_->cgl_context());
   context_ = nil;
@@ skipping 42 matching lines @@
   if (!renderWidgetHostView_->compositing_iosurface_->DrawIOSurface(
         context_,
         window_rect,
         window_scale_factor,
         false)) {
     renderWidgetHostView_->GotAcceleratedCompositingError();
   }
 }
 
 @end