Add google-code-prettify lib checkout, required by core-doc-viewer (and core-component page).
Add google-code-prettify lib checkout, required by core-doc-viewer (and
core-component page).

Polymer/tools,Polymer/tools,Polymer/tools,Polymer/tools,imrehorvath/tools,imrehorvath/tools,jorgecasar/tools,jorgecasar/tools