UserAgent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:46.0) Gecko/20100101 Firefox/46.0

Steps to reproduce the problem:
1. export LDFLAGS="..."
2. run gyp_chromium

What is the expected behavior?
In cross compilation, LDFLAGS should only be passed to cross compiler, just as how CFLAGS works.

What went wrong?
LDFLAGS is also used in building host tools.

Did this work before? No 

Chrome version:   Channel: n/a
OS Version: 
Flash Version: 

For building host tools, we can control the flags passed to CC_host/CXX_host by setting environment variables like CPPFLAGS_host, CFLAGS_host and CXXFLAGS_host. The same mechanism should be implemented for the linker (and maybe other tools used in building host tools).