gpu: Add CHROMIUM_copy_image extension.

gpu/GLES2/extensions/CHROMIUM/CHROMIUM_copy_image.txt

+Name
+
+    CHROMIUM_copy_image
+
+Name Strings
+
+    GL_CHROMIUM_copy_image
+
+Version
+
+    Last Modified Date: October 9, 2016
+
+Dependencies
+
+    OpenGL ES 2.0 is required.
+
+    Requires the CHROMIUM_image extension.
+
+    Requires the CHROMIUM_fence extension.
+
+Overview
+
+    This extension provides a mechanism for copying images to texture targets.
+
+Issues
+
+    None
+
+New Tokens
+
+    None
+
+New Procedures and Functions
+
+    The command
+
+        void CopyImageSubData(GLint source_image_id,
+                              GLint dest_texture_id,
+                              GLint xoffset, GLint yoffset,
+                              GLint x, GLint y,
+                              GLsizei width, GLsizei height,
+                              GLint in_fence_id, GLint out_fence_id);
+
+    may be used to copy a region of image to a texture object.
+
+    CopyImageSubData does not perform general-purpose conversions
+    such as scaling, resizing, blending, color-space, or format
+    conversions. It should be considered to operate in a manner
+    similar to a CPU memcpy.
+
+    If <in_fence_id> is non-zero then the copy operation is deferred
+    until the condition of the sync object referenced by
+    <in_fence_id> is satisfied. If <out_fence_id> is non-zero then
+    the sync object referenced by <out_fence_id> will be signaled
+    when copy operation has completed.
+
+    <xoffset> and <yoffset> specify a texel offset in the x and y
+    direction respectively within the destination texture.
+
+    <x> and <y> specify an offset in the x and y direction
+    respectively within the source image.
+
+    <width> specifies the width of the subimage.
+
+    <height> specifies the width of the subimage.
+
+    INVALID_OPERATION is generated if <image_id> is not a valid image id.
+
+    INVALID_OPERATION is generated if image format and destination
+    Internal format are not one of the valid formats described above.
+
+    INVALID_OPERATION is generated if the destination texture has not been
+    defined.
+
+    INVALID_VALUE is generated if <dest_texture_id> texture is not defined.
+
+    INVALID_VALUE is generated if <dest_texture_id> texture is not bound as
+    GL_TEXTURE_2D or GL_TEXTURE_RECTANGLE_ARB.
+
+    INVALID_VALUE is generated if <xoffset> < 0 , or <yoffset> < 0.
+
+    INVALID_VALUE is generated if (<xoffset> + <width>) > dest_width,
+    or (<yoffset> + <height>) > dest_height.
+
+
+Errors
+
+    None.
+
+New State
+
+    None.
+
+Revision History
+
+    10/9/2016    Documented the extension