gpu: More specific internalformat requirements for CreateImageCHROMIUM.

gpu/GLES2/extensions/CHROMIUM/CHROMIUM_image.txt

Index: gpu/GLES2/extensions/CHROMIUM/CHROMIUM_image.txt
diff --git a/gpu/GLES2/extensions/CHROMIUM/CHROMIUM_image.txt b/gpu/GLES2/extensions/CHROMIUM/CHROMIUM_image.txt
index 2974e43bd32b7d01d4384cb62c7011a90d07a660..645a3f42fc1aa3d6e749e5bf1ad7113935f77623 100644
--- a/gpu/GLES2/extensions/CHROMIUM/CHROMIUM_image.txt
+++ b/gpu/GLES2/extensions/CHROMIUM/CHROMIUM_image.txt
@@ -14,6 +14,8 @@ Dependencies
 
     OpenGL ES 2.0 is required.
 
+    EXT_texture_format_BGRA8888 affects the definition of this extension.
+
 Overview
 
     This extension defines a new resource type that is suitable for
@@ -43,7 +45,7 @@ New Procedures and Functions
     INVALID_VALUE is generated if <width> or <height> is nonpositive.
 
     INVALID_ENUM is generated if <internalformat> is not one of
-    RGB or RGBA.
+    RGB, RGBA or GL_BGRA_EXT.
 
     void DestroyImageCHROMIUM(GLuint image_id)
 
@@ -51,6 +53,11 @@ New Procedures and Functions
 
     INVALID_OPERATION is generated if <image_id> is not a valid image id.
 
+Dependencies on EXT_texture_format_BGRA8888
+
+    If EXT_texture_format_BGRA8888 is not supported:
+     * delete any reference to the GL_BGRA_EXT format.
+
 Errors
 
     None.
@@ -64,3 +71,4 @@ Revision History
     5/9/2013    Documented the extension
     4/30/2014   Moved usage flag to creation function.
     10/7/2014   Remove map/unmap API.
+    4/6/2015    Add GL_BGRA_EXT format.