compositor_unittests target is unimplmented on Mac

ui/gfx/gl/gl_surface_nsview.mm

Index: ui/gfx/gl/gl_surface_nsview.mm
diff --git a/ui/gfx/gl/gl_surface_nsview.mm b/ui/gfx/gl/gl_surface_nsview.mm
new file mode 100644
index 0000000000000000000000000000000000000000..c87486593e4788901092edc5c9ab00c1a4a360a0
--- /dev/null
+++ b/ui/gfx/gl/gl_surface_nsview.mm
@@ -0,0 +1,45 @@
+// 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 "ui/gfx/gl/gl_surface_nsview.h"
+
+#import <AppKit/NSView.h>
+
+#include "base/basictypes.h"
+#include "base/logging.h"
+#include "base/mac/mac_util.h"
+#include "ui/gfx/gl/gl_bindings.h"
+#include "ui/gfx/gl/gl_context.h"
+
+namespace gfx {
+
+GLSurfaceNSView::GLSurfaceNSView(PluginWindowHandle view)
+    : view_(view) {
+}
+
+GLSurfaceNSView::~GLSurfaceNSView() {
+}
+
+void GLSurfaceNSView::Destroy() {
+}
+
+bool GLSurfaceNSView::IsOffscreen() {
+  return false;
+}
+
+bool GLSurfaceNSView::SwapBuffers() {
+  CGLContextObj cgl_context = CGLGetCurrentContext();
+  CGLFlushDrawable(cgl_context);

[Ken Russell (switch to Gerrit), 2011/11/17 00:14:40]

I don't think it's valid to assume that flushing the CGL context will take care
of all of the necessary bookkeeping at the AppKit level. I'd suggest either
keeping a weak pointer to the current GLContextNSView in the surface, calling a
new FlushBuffer method on that instance, and implementing it properly there; or
minimally calling [[NSOpenGLContext currentContext] flushBuffer].

[dhollowa, 2011/11/17 01:41:51]

Done.  I went with the weak pointer approach.  It involved a down-cast but seems
more resistant to bugs where the scoped context is not set properly.

+  return true;
+}
+
+gfx::Size GLSurfaceNSView::GetSize() {
+  return gfx::Size(NSSizeToCGSize([view_ bounds].size));
+}
+
+void* GLSurfaceNSView::GetHandle() {
+  return view_;
+}
+
+}  // namespace gfx