Add subscribeUniform extension pipeline

gpu/GLES2/extensions/CHROMIUM/CHROMIUM_subscribe_uniform.txt

+Name
+
+    CHROMIUM_subscribe_uniform
+
+Name Strings
+
+    CHROMIUM_subscribe_uniform
+
+Version
+
+    Last Modifed Date: October 15, 2014
+
+Dependencies
+
+    OpenGL ES 2.0 is required.
+
+Overview
+
+    Allows clients to subscribe to a set of input uniforms which will be
+    automatically populated in their Shaders by the GPU Service.

[piman, 2014/10/16 02:39:18]

automatically populated when?

[orglofch, 2014/10/21 04:19:38]

Updated to reflect new API.

+    Decreases percieved latency for operations performed against these
+    uniforms.
+
+New Tokens
+
+    Accepted by the <target> parameter of SubscribeUniformChromium:
+
+    MOUSE_POSITION                                      0x924B
+    MOUSE_DELTA                                         0x924C
+
+New Procedures and Functions
+
+    The command   
+
+        void glSubscribeUniformCHROMIUM (GLenum target, const GLchar* name)
+
+    Associates an internal uniform with a supplied name. The name will be
+    the name given to the uniform and used to populate it internally.
+    <target> Is the uniform the client wants to have populated.
+    <name> Is the name the client wants to use for the uniform.

[piman, 2014/10/16 02:39:17]

Uniform of which shader/program? The current one? All of them?

[orglofch, 2014/10/21 04:19:38]

Updated to reflect new API.

+
+Errors
+
+    None.
+
+New State
+
+    None.
+
+Revision History
+
+    10/15/2014    Documented the extension