There may be instances where CEF requires changes to the Chromium/WebKit code base that are not desired by the Chromium/WebKit projects as a whole. To address this situation the CEF project adds a patch capability as part of the CEF GYP project generation step. The patch capability works as follows: 1. The CEF developer creates one or more patch files containing all required changes to the Chromium/WebKit code base and places those patch files in the "patches" subdirectory. 2. The CEF developer adds an entry for each patch file in the "patch.cfg" file. 3. CEF applies the patches to the Chromium/WebKit source tree using the patcher.py tool in the tools directory. If necessary the patcher.py tool also rewrites the "patch_state.h" file which defines the CEF_PATCHES_APPLIED preprocessor value. To disable automatic application of patches to the Chromium/WebKit code base create an empty "NOPATCH" file in the "patch" directory. Sections of the CEF code base that otherwise require patches will be disabled using the CEF_PATCHES_APPLIED preprocessor value defined in the "patch_state.h" file. Be warned that not applying all required patches may break important CEF functionality.