Attempt to fix v8 build.

Can't try locally (no disk space right now)

v8pp/build-v8.sh

 
 set -ex
 
-export PATH=`pwd`/depot_tools:"$PATH"
+# I guess now we have to install ninja ourselves.. sigh..
+git clone git://github.com/ninja-build/ninja.git
+pushd ninja
+git checkout v1.11.1
+
+cmake -Bbuild-cmake
+cmake --build build-cmake
+export PATH=`pwd`/build-cmake:"$PATH"  # ninja available now
+
+export PATH=`pwd`/depot_tools:"$PATH"  # depot tools available now (used to include ninja)
 
 # https://github.com/prahladyeri/tuxdrive/issues/3
 apt-get install python3-pip -y