i found the project at https://github.com/GoogleChrome/custom-tabs-client
after clone it and compile the project with :
aa@kkk:~/wk/custom-tabs-client$ ./gradlew assembleDebug

compile failed with many error: package R does not exist:
/home/sinsv/wk/custom-tabs-client/customtabs/src/android/support/customtabs/browseractions/BrowserActionsFallbackMenuAdapter.java:64: error: package R does not exist
                    R.layout.browser_actions_context_menu_row, null);

Device: 
ubuntu 14

Steps to reproduce: 
clone the project, compile it
Observed behavior: 
compile failed
Expected behavior: 
compile ok and a apk generated
Frequency: 
100%

Additional comments: