Add GL_EXT_unpack_subimage support to command buffer client code.

gpu/GLES2/extensions/CHROMIUM/CHROMIUM_flipy.txt

 Name
 
     CHROMIUM_flipy
 
 Name Strings
 
     GL_CHROMIUM_flipy
 
 Version
 
-    Last Modifed Date: July 22, 2011
+    Last Modifed Date: April 9, 2012
 
 Dependencies
 
     OpenGL ES 2.0 is required.
 
 Overview
 
     This extension adds the ability to vertically flip texture image data when
     calling TexImage2D and TexSubImage2D.
 
 Issues
 
 
 New Tokens
 
     Accepted by the <param> parameter of PixelStorei:
 
         UNPACK_FLIP_Y_CHROMIUM              0x9240
 
+Additions to the OpenGL ES 2.0 Specification
+
+    Modifications to Table 3.1 (PixelStore Parameters)
+
+        Add the following entry:
+
+        Parameter Name                   Type      Initial Value  Valid Range
+        ==============                   ====      =============  ===========
+        UNPACK_FLIP_Y_CHROMIUM           boolean   FALSE          {TRUE, FALSE}
+
+    Modifications to 3.6.2 Transfer of Pixel Rectangles, in the Unpacking
+    section:
+
+    Change
+        "If p indicates the location in memory of the first element of the first
+        row, then the first element of the Nth row is indicated by
+                            p + Nk (3.9)"
+    to
+        "If p indicates the location in memory of the first element of the first
+        row, then the first element of the Nth row is indicated by
+                            p + Nk (3.9)
+        if UNPACK_FLIP_Y is FALSE. Otherwise, the first element of the Nth row
+        is indicated by
+                            p - Nk (3.10)
+
+    After the sentence
+
+        "If the number of bits per element is not 1, 2, 4, or 8 times the number
+        of bits in a GL ubyte, then k = nl for all values of a."
+
+    insert:
+
+        "If UNPACK_FLIP_Y_CHROMIUM is FALSE then p is equal to pixels. Otherwise
+        p is pixels + (height - 1)k."
+
+Interactions with GL_EXT_unpack_subimage
+
+    Do not add the sentence "If UNPACK_FLIP_Y_CHROMIUM is FALSE ..." described
+    in this extension. Instead do the following after applying
+    GL_EXT_unpack_subimage:
+
+    Change
+
+         "There is a mechanism for selecting a sub-rectangle of groups
+          from a larger containing rectangle. This mechanism relies on
+          three integer parameters: UNPACK_ROW_LENGTH, UNPACK_SKIP_ROWS,
+          and UNPACK_SKIP_PIXELS. Before obtaining the first group from
+          memory, the pointer supplied to TexImage2D is effectively
+          advanced by (UNPACK_SKIP_PIXELS)n + (UNPACK_SKIP_ROWS)k
+          elements. Then <width> groups are obtained from contiguous
+          elements in memory (without advancing the pointer), after
+          which the pointer is advanced by k elements. <height> sets of
+          <width> groups of values are obtained this way. See figure
+          3.6."
+
+    to
+
+         "There is a mechanism for selecting a sub-rectangle of groups
+          from a larger containing rectangle. This mechanism relies on
+          three integer parameters: UNPACK_ROW_LENGTH, UNPACK_SKIP_ROWS,
+          and UNPACK_SKIP_PIXELS. IF UNPACK_FLIP_Y_CHROMIUM is FALSE then
+          p, the location of the first element of the first
+          group, is pixels + (UNPACK_SKIP_PIXELS)n + (UNPACK_SKIP_ROWS)k.
+          When UNPACK_FLIP_Y_CHROMIUM is TRUE then p is pixels +
+          (UNPACK_SKIP_PIXELS)n + (UNPACK_SKIP_ROWS + height - 1)k. After
+          p is determined <width> groups are obtained from contiguous
+          elements in memory (without advancing the pointer), after which
+          the pointer is advanced by +/-k elements depending on the value
+          of UNPACK_CHROMIUM_FLIP_Y. <height> sets of <width> groups of
+          values are obtained this way. See figure 3.6."
+
 New Procedures and Functions
 
     None.
 
 Errors
 
     None.
 
 New State
 
     None.
 
 Revision History
 
     7/22/2011    Documented the extension
+    4/09/2012    Added more documentation and described interactions with
+                 GL_EXT_unpack_subimage