compositor_unittests target is unimplmented on Mac

ui/gfx/gl/gl_context_mac.mm

 // Copyright (c) 2011 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 "base/basictypes.h"
 #include "base/logging.h"
 #include "base/mac/mac_util.h"
 #include "base/memory/scoped_generic_obj.h"
 #include "base/memory/scoped_ptr.h"
 #include "third_party/mesa/MesaLib/include/GL/osmesa.h"
 #include "ui/gfx/gl/gl_bindings.h"
 #include "ui/gfx/gl/gl_context_cgl.h"
 #include "ui/gfx/gl/gl_context_osmesa.h"
 #include "ui/gfx/gl/gl_context_stub.h"
 #include "ui/gfx/gl/gl_implementation.h"
-#include "ui/gfx/gl/gl_surface_cgl.h"
-#include "ui/gfx/gl/gl_surface_osmesa.h"
+#include "ui/gfx/gl/gl_surface.h"
+
+#if defined(USE_WEBKIT_COMPOSITOR)
+#include "ui/gfx/gl/gl_context_nsview.h"
+#endif
 
 namespace {
 
 // ScopedGenericObj functor for CGLDestroyRendererInfo().
 class ScopedDestroyRendererInfo {
  public:
   void operator()(CGLRendererInfoObj x) const {
     CGLDestroyRendererInfo(x);
   }
 };
 
 }  // namespace
 
 namespace gfx {
 
 class GLShareGroup;
 
 scoped_refptr<GLContext> GLContext::CreateGLContext(
     GLShareGroup* share_group,
     GLSurface* compatible_surface,
     GpuPreference gpu_preference) {
   switch (GetGLImplementation()) {
     case kGLImplementationDesktopGL: {
-      scoped_refptr<GLContext> context(new GLContextCGL(share_group));
-      if (!context->Initialize(compatible_surface, gpu_preference))
-        return NULL;
+      scoped_refptr<GLContext> context;
+      if (compatible_surface->IsOffscreen()) {
+        context = new GLContextCGL(share_group);
+        if (!context->Initialize(compatible_surface, gpu_preference))
+          return NULL;
+      } else {
+#if defined(USE_WEBKIT_COMPOSITOR)

[piman, 2011/11/16 20:55:59]

I don't think USE_WEBKIT_COMPOSITOR ought to have any impact here.
USE_WEBKIT_COMPOSITOR is whether ui::Compositor is implemented using WebKit or
the "old" compositor. But It shouldn't have any impact on the context
implementation, which is lower in the stack.
In particular this code is used in the GPU process as well, where
USE_WEBKIT_COMPOSITOR has absolutely no meaning.

What would happen if this code was enabled in all cases?

[dhollowa, 2011/11/16 23:28:59]

Due to the different definition of the PluginWindowHandle type, compilation of
GLSurfaceNSView fails in the use_aura=0 case (see my comment in
native_widget_types.h).  Since GLSurfaceNSView and GLContextNSView only work
together, I feel it is best to only compile and link them in to a given
configuration as a pair.

Note, I've change this and elsewhere to "USE_AURA" instead of
"USE_WEBKIT_COMPOSITOR" to better reflect that this is a platform difference,
not just a configuration difference.

On 2011/11/16 20:55:59, piman wrote:

+        context = new GLContextNSView(share_group);
+        if (!context->Initialize(compatible_surface, gpu_preference))
+          return NULL;
+#endif
+      }
 
       return context;
     }
     case kGLImplementationOSMesaGL: {
       scoped_refptr<GLContext> context(new GLContextOSMesa(share_group));
       if (!context->Initialize(compatible_surface, gpu_preference))
         return NULL;
 
       return context;
     }
@@ skipping 80 matching lines @@
   }
 
   if (found_online && found_offline) {
     supports_dual_gpus = true;
   }
 
   return supports_dual_gpus;
 }
 
 }  // namespace gfx