Android: Update docs to say Java 8 is required

build/install-build-deps-android.sh

 #!/bin/bash -e
 
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Script to install everything needed to build chromium on android, including
 # items requiring sudo privileges.
 # See https://www.chromium.org/developers/how-tos/android-build-instructions
 
 # This script installs the sun-java6 packages (bin, jre and jdk). Sun requires
 # a license agreement, so upon installation it will prompt the user. To get
 # past the curses-based dialog press TAB <ret> TAB <ret> to agree.
 
 args="$@"
 
 if ! uname -m | egrep -q "i686|x86_64"; then
   echo "Only x86 architectures are currently supported" >&2
   exit
 fi
 
+function IsJava8() {
+  # Arg is either java or javac
+  $1 -version 2>&1 | grep '1\.8' > /dev/null

[jbudorick, 2017/01/31 21:51:35]

grep -q ?

[agrieve, 2017/02/01 02:39:20]

Done.

+}
+
 lsb_release=$(lsb_release --codename --short)
 
-case $lsb_release in
-  xenial|yakkety)
-    java_alternative="java-1.8.0-openjdk-amd64"
-    java_pkgs="openjdk-8-jre openjdk-8-jdk"
-  ;;
-  *)
-    java_alternative="java-1.7.0-openjdk-amd64"
-    java_pkgs="openjdk-7-jre openjdk-7-jdk"
-  ;;
-esac
-
 # Install first the default Linux build deps.
 "$(dirname "${BASH_SOURCE[0]}")/install-build-deps.sh" \
   --no-syms --lib32 --no-arm --no-chromeos-fonts --no-nacl --no-prompt "${args}"
 
-# The temporary directory used to store output of update-java-alternatives
-TEMPDIR=$(mktemp -d)
-cleanup() {
-  local status=${?}
-  trap - EXIT
-  rm -rf "${TEMPDIR}"
-  exit ${status}
-}
-trap cleanup EXIT
-
 # Fix deps
 sudo apt-get -f install
 
 # Install deps
 # This step differs depending on what Ubuntu release we are running
 # on since the package names are different, and Sun's Java must
 # be installed manually on late-model versions.
 
 # common
 sudo apt-get -y install lib32z1 lighttpd python-pexpect xvfb x11-utils
 
 # Some binaries in the Android SDK require 32-bit libraries on the host.
 # See https://developer.android.com/sdk/installing/index.html?pkg=tools
 if [[ $lsb_release == "precise" ]]; then
   sudo apt-get -y install ia32-libs
 else
   sudo apt-get -y install libncurses5:i386 libstdc++6:i386 zlib1g:i386
 fi
 
+# Required by //components/cronet/tools/generate_javadoc.py
+# TODO(375324): Stop requiring ANT.
 sudo apt-get -y install ant
 
-# Install openjdk and openjre stuff
-sudo apt-get -y install $java_pkgs
-
-# Switch version of Java to openjdk 7.
-# Some Java plugins (e.g. for firefox, mozilla) are not required to build, and
-# thus are treated only as warnings. Any errors in updating java alternatives
-# which are not '*-javaplugin.so' will cause errors and stop the script from
-# completing successfully.
-if ! sudo update-java-alternatives -s $java_alternative \
-           >& "${TEMPDIR}"/update-java-alternatives.out
-then
-  # Check that there are the expected javaplugin.so errors for the update
-  if grep 'javaplugin.so' "${TEMPDIR}"/update-java-alternatives.out >& \
-      /dev/null
-  then
-    # Print as warnings all the javaplugin.so errors
-    echo 'WARNING: java-6-sun has no alternatives for the following plugins:'
-    grep 'javaplugin.so' "${TEMPDIR}"/update-java-alternatives.out
-  fi
-  # Check if there are any errors that are not javaplugin.so
-  if grep -v 'javaplugin.so' "${TEMPDIR}"/update-java-alternatives.out \
-      >& /dev/null
-  then
-    # If there are non-javaplugin.so errors, treat as errors and exit
-    echo 'ERRORS: Failed to update alternatives for java-6-sun:'
-    grep -v 'javaplugin.so' "${TEMPDIR}"/update-java-alternatives.out
-    exit 1
-  fi
+if ! (IsJava8 java && IsJava8 javac); then
+  sudo apt-get -y install openjdk-8-jre openjdk-8-jdk

[jbudorick, 2017/01/31 21:51:34]

This will just fail on 14.04 or earlier.

[agrieve, 2017/02/01 02:39:21]

Expanded the error message.

This also made me realize there's a -e at the top of the file, which I've moved
to its own command to be more noticeable. 

 fi
 
+# Assume java8 still not reporting being there means update-java-alternatives

[jbudorick, 2017/01/31 21:51:35]

Doing this before any of the bots switch & when such a switch isn't imminent
seems unwise.

[agrieve, 2017/02/01 02:39:21]

Folded into an error message. Given that this isn't run by any bots (I don't
think it is anyways...), I figured it'd be fine to update. Happy to sit on it as
well though until the bot rollout if further along.

[jbudorick, 2017/02/01 16:30:39]

It isn't run on the bots, but I'd prefer that we update this around the same
time that we update chromium.android + chromium.linux.

+# needs to be run.
+if ! IsJava8 javac; then
+  sudo update-java-alternatives -s java-1.8.0-openjdk-amd64
+fi
+
+if ! IsJava8 javac; then
+  echo "Failed to install javac 1.8. javac -version reports:"
+  javac -version
+  exit 1
+fi
 echo "install-build-deps-android.sh complete."