Use sensible default locations for Java

Use sensible default locations for Java based on
the EXPERIMENTAL_USE_JAVA8 flag.

Bug: 25786468
Change-Id: I7ec035b5329785efc41b3f971d5e3ae202293576
diff --git a/envsetup.sh b/envsetup.sh
index f838d62..e569024 100644
--- a/envsetup.sh
+++ b/envsetup.sh
@@ -1407,11 +1407,7 @@
     \cd $T/$pathname
 }
 
-# Force JAVA_HOME to point to java 1.7 if it isn't already set.
-#
-# Note that the MacOS path for java 1.7 includes a minor revision number (sigh).
-# For some reason, installing the JDK doesn't make it show up in the
-# JavaVM.framework/Versions/1.7/ folder.
+# Force JAVA_HOME to point to java 1.7/1.8 if it isn't already set.
 function set_java_home() {
     # Clear the existing JAVA_HOME value if we set it ourselves, so that
     # we can reset it later, depending on the version of java the build
@@ -1424,14 +1420,25 @@
     fi
 
     if [ ! "$JAVA_HOME" ]; then
-      case `uname -s` in
-          Darwin)
-              export JAVA_HOME=$(/usr/libexec/java_home -v 1.7)
-              ;;
-          *)
-              export JAVA_HOME=/usr/lib/jvm/java-7-openjdk-amd64
-              ;;
-      esac
+      if [ ! "$EXPERIMENTAL_USE_JAVA8" ]; then
+        case `uname -s` in
+            Darwin)
+                export JAVA_HOME=$(/usr/libexec/java_home -v 1.7)
+                ;;
+            *)
+                export JAVA_HOME=/usr/lib/jvm/java-7-openjdk-amd64
+                ;;
+        esac
+      else
+        case `uname -s` in
+            Darwin)
+                export JAVA_HOME=$(/usr/libexec/java_home -v 1.8)
+                ;;
+            *)
+                export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64
+                ;;
+        esac
+      fi
 
       # Keep track of the fact that we set JAVA_HOME ourselves, so that
       # we can change it on the next envsetup.sh, if required.