gpu: Add CHROMIUM_texture_from_image spec and fence support.

gpu/GLES2/extensions/CHROMIUM/CHROMIUM_texture_from_image.txt

+Name
+
+    CHROMIUM_texture_from_image
+
+Name Strings
+
+    GL_CHROMIUM_texture_from_image
+
+Version
+
+    Last Modified Date: October 2, 2016
+
+Dependencies
+
+    OpenGL ES 2.0 is required.
+
+    Requires the CHROMIUM_image extension.
+
+Overview
+
+    This extension provides a mechanism for creating image texture targets
+    from GL images.
+
+Issues
+
+    None
+
+New Tokens
+
+    None
+
+New Procedures and Functions
+
+    The command
+
+        void BindTexImage2DCHROMIUM(GLenum target,
+                                    GLint image_id,
+                                    GLint fence_id)
+
+    defines a two-dimensional texture image.  The texture image is taken
+    from <image_id> and need not be copied. If <fence_id> is non-zero then
+    the bind operation is deferred until the condition of the sync object
+    referenced by <fence_id> is satisfied.
+
+    INVALID_OPERATION is generated if no texture is bound to <target>.
+
+    INVALID_OPERATION is generated if <image_id> is not a valid image id.
+
+    To release an image that is being used as a texture, call
+
+        void ReleaseTexImage2DCHROMIUM(GLenum target,
+                                       GLint image_id)
+
+    INVALID_OPERATION is generated if no texture is bound to <target>.
+
+    INVALID_OPERATION is generated if <image_id> is not a valid image id.
+
+Errors
+
+    None.
+
+New State
+
+    None.
+
+Revision History
+
+    10/2/2016    Documented the extension