Add GL_TEXTURE_EXTERNAL_OES as supported texture target for CHROMIUM_map_image.

ui/gl/gl_image_shm.h

Index: ui/gl/gl_image_shm.h
diff --git a/ui/gl/gl_image_shm.h b/ui/gl/gl_image_shm.h
index efff1ed52bc1f251152a0c122cb592c6e93dffa2..b750ccdcd4a427fb3602fd6d5c5b664d9305d961 100644
--- a/ui/gl/gl_image_shm.h
+++ b/ui/gl/gl_image_shm.h
@@ -6,6 +6,7 @@
 #define UI_GL_GL_IMAGE_SHM_H_
 
 #include "base/memory/scoped_ptr.h"
+#include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_image.h"
 
 namespace gfx {
@@ -31,6 +32,8 @@ class GL_EXPORT GLImageShm : public GLImage {
   scoped_ptr<base::SharedMemory> shared_memory_;
   gfx::Size size_;
   unsigned internalformat_;
+  GLuint egl_texture_id_;
+  EGLImageKHR egl_image_;
 
   DISALLOW_COPY_AND_ASSIGN(GLImageShm);
 };