Expose MGL interface through NaCl IRT

mojo/public/platform/nacl/mojo_irt.h

Index: mojo/public/platform/nacl/mojo_irt.h
diff --git a/mojo/public/platform/nacl/mojo_irt.h b/mojo/public/platform/nacl/mojo_irt.h
index db3a180ffd333748115a2fc18647b4360d56271b..df497ba6629c6d1a5caf1a8eb808af5dab1e97f7 100644
--- a/mojo/public/platform/nacl/mojo_irt.h
+++ b/mojo/public/platform/nacl/mojo_irt.h
@@ -8,6 +8,8 @@
 #ifndef MOJO_PUBLIC_PLATFORM_NACL_MOJO_IRT_H_
 #define MOJO_PUBLIC_PLATFORM_NACL_MOJO_IRT_H_
 
+#include "mojo/public/c/gpu/MGL/mgl.h"
+#include "mojo/public/c/gpu/MGL/mgl_onscreen.h"
 #include "mojo/public/c/system/buffer.h"
 #include "mojo/public/c/system/data_pipe.h"
 #include "mojo/public/c/system/message_pipe.h"
@@ -85,6 +87,28 @@ struct nacl_irt_mojo {
   MojoResult (*_MojoGetInitialHandle)(MojoHandle* handle);
 };
 
+#define NACL_IRT_MGL_v0_1 "nacl-irt-mgl-0.1"
+
+struct nacl_irt_mgl {
+  MGLContext (*MGLCreateContext)(MGLOpenGLAPIVersion version,

[Mark Seaborn, 2015/10/17 01:08:08]

Can you add comments to document what these functions do, or point to
documentation elsewhere?  How do these functions handle errors?

[Petr Hosek, 2015/10/17 01:51:13]

Done.

[Mark Seaborn, 2015/10/20 01:24:32]

I suppose I should have put the emphasis on "point to documentation elsewhere".
:-)  The new version duplicates comments, which isn't great, because they will
inevitably get out of sync.  Can you point to the existing comments instead?

+                                 MojoHandle command_buffer_handle,
+                                 MGLContext share_group,
+                                 MGLContextLostCallback lost_callback,
+                                 void* lost_callback_closure,
+                                 const struct MojoAsyncWaiter* async_waiter);
+  void (*MGLDestroyContext)(MGLContext context);
+  void (*MGLMakeCurrent)(MGLContext context);
+  MGLContext (*MGLGetCurrentContext)(void);
+  MGLMustCastToProperFunctionPointerType (*MGLGetProcAddress)(const char* name);
+};
+
+#define NACL_IRT_MGL_ONSCREEN_v0_1 "nacl-irt-mgl-onscreen-0.1"
+
+struct nacl_irt_mgl_onscreen {
+  void (*MGLResizeSurface)(uint32_t width, uint32_t height);

[Mark Seaborn, 2015/10/17 01:08:08]

Same comment about docs...

What surface does this operate on?  What does MGLSwapBuffers() operate on?  It
looks like these operate on global state.

[Petr Hosek, 2015/10/17 01:51:13]

Done.

+  void (*MGLSwapBuffers)(void);
+};
+
 #ifdef __cplusplus
 extern "C" {
 #endif