Adds support for the GL_ANGLE_texture_usage and GL_EXT_texture_storage

gpu/command_buffer/client/gles2_cmd_helper_autogen.h

Index: gpu/command_buffer/client/gles2_cmd_helper_autogen.h
===================================================================
--- gpu/command_buffer/client/gles2_cmd_helper_autogen.h	(revision 112643)
+++ gpu/command_buffer/client/gles2_cmd_helper_autogen.h	(working copy)
@@ -1151,6 +1151,13 @@
     c.Init(target, samples, internalformat, width, height);
   }
 
+  void TexStorage2DEXT(
+      GLenum target, GLsizei levels, GLint internalFormat, GLsizei width,
+      GLsizei height) {
+    gles2::TexStorage2DEXT& c = GetCmdSpace<gles2::TexStorage2DEXT>();
+    c.Init(target, levels, internalFormat, width, height);
+  }
+
   void SwapBuffers() {
     gles2::SwapBuffers& c = GetCmdSpace<gles2::SwapBuffers>();
     c.Init();