Adds support for the GL_ANGLE_texture_usage and GL_EXT_texture_storage

gpu/command_buffer/service/gl_utils.h

Index: gpu/command_buffer/service/gl_utils.h
===================================================================
--- gpu/command_buffer/service/gl_utils.h	(revision 112643)
+++ gpu/command_buffer/service/gl_utils.h	(working copy)
@@ -45,6 +45,27 @@
 // GL_ANGLE_pack_reverse_row_order
 #define GL_PACK_REVERSE_ROW_ORDER_ANGLE    0x93A4
 
+// GL_ANGLE_texture_usage
+#define GL_TEXTURE_USAGE_ANGLE                 0x93A2
+#define GL_FRAMEBUFFER_ATTACHMENT_ANGLE        0x93A3
+
+// GL_EXT_texture_storage
+#define GL_TEXTURE_IMMUTABLE_FORMAT_EXT        0x912F
+#define GL_ALPHA8_EXT                          0x803C
+#define GL_LUMINANCE8_EXT                      0x8040
+#define GL_LUMINANCE8_ALPHA8_EXT               0x8045
+#define GL_RGBA32F_EXT                         0x8814
+#define GL_RGB32F_EXT                          0x8815
+#define GL_ALPHA32F_EXT                        0x8816
+#define GL_LUMINANCE32F_EXT                    0x8818
+#define GL_LUMINANCE_ALPHA32F_EXT              0x8819
+#define GL_RGBA16F_EXT                         0x881A
+#define GL_RGB16F_EXT                          0x881B
+#define GL_ALPHA16F_EXT                        0x881C
+#define GL_LUMINANCE16F_EXT                    0x881E
+#define GL_LUMINANCE_ALPHA16F_EXT              0x881F
+#define GL_BGRA8_EXT                           0x93A1
+
 #define GL_GLEXT_PROTOTYPES 1
 
 // Define this for extra GL error debugging (slower).