If you are receiving this error msg compiling Android:
external/gtest/src/../include/gtest/internal/gtest-param-util.h:122:11: error: ‘ptrdiff_t’ does not name a type
Then just add “#include <cstddef>” inside these files:
external/gtest/include/gtest/internal/gtest-param-util.h external/chromium/testing/gtest/include/gtest/internal/gtest-param-util.h external/llvm/utils/unittest/googletest/include/gtest/internal/gtest-param-util.h external/protobuf/gtest/include/gtest/internal/gtest-param-util.h
Source: https://groups.google.com/forum/#!msg/android-building/AgeruY7XIwQ/5_GiCN9UtLUJ