Added support for the GL_TEXTURE_EXTERNAL target

This will allow us to support YUV surfaces.

Change-Id: I2d4da75f1006a5285bdc552695d4caeecccf2183
diff --git a/libs/surfaceflinger/LayerDim.cpp b/libs/surfaceflinger/LayerDim.cpp
index d528d2f..906a583 100644
--- a/libs/surfaceflinger/LayerDim.cpp
+++ b/libs/surfaceflinger/LayerDim.cpp
@@ -119,6 +119,9 @@
         glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
         glColor4x(0, 0, 0, alpha);
         
+#if defined(GL_OES_texture_external)
+        glDisable(GL_TEXTURE_EXTERNAL_OES);
+#endif
 #if defined(DIM_WITH_TEXTURE) && defined(EGL_ANDROID_image_native_buffer)
         if (sUseTexture) {
             glBindTexture(GL_TEXTURE_2D, sTexId);