Use the most recent version of ADB from the SDK if necessary.

This removes ADB from the Skia checkout and also does some quick
checks to make sure the version of ADB used meets a minimum threshold

Review URL: https://codereview.chromium.org/692513003

platform_tools/android/bin/utils/setup_adb.sh

@@ -5,13 +5,31 @@ UTIL_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 
 if [ "$(which adb)" != "" ]; then
     ADB="$(which adb)"
-elif [ $(uname) == "Linux" ]; then
-    ADB=$UTIL_DIR/../linux/adb
-elif [ $(uname) == "Darwin" ]; then
-    ADB=$UTIL_DIR/../mac/adb
+elif [ -d "$ANDROID_SDK_ROOT" ]; then
+    ADB="${ANDROID_SDK_ROOT}/platform-tools/adb"
 else
-    echo "ERROR: Could not find ADB!"
-    exit 1;
+  echo $ANDROID_SDK_ROOT
+  echo "No ANDROID_SDK_ROOT set (check that android_setup.sh was properly sourced)"
+  exit 1
 fi
 
-#echo "ADB is: $ADB"
+if [ ! -x $ADB ]; then
+  echo "The adb binary is not executable"
+  exit 1
+fi
+
+if [ $(uname) == "Linux" ]; then
+  ADB_REQUIRED="1.0.32"
+elif [ $(uname) == "Darwin" ]; then
+  ADB_REQUIRED="1.0.31"
+fi
+
+# get the version and then truncate it to be just the version numbers
+ADB_VERSION="$($ADB version)"
+ADB_VERSION="${ADB_VERSION##* }"
+
+if [ $ADB_VERSION != $ADB_REQUIRED ]; then
+  echo "WARNING: Your ADB version is out of date!"
+  echo "  Expected ADB Version: ${ADB_REQUIRED}"
+  echo "  Actual ADB Version: ${ADB_VERSION}"
+fi