[Android] Roll to NDK r12b.

build/android/adb_gdb

 #!/bin/bash
 #
 # 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.
 #
 
 # A generic script used to attach to a running Chromium process and
 # debug it. Most users should not use this directly, but one of the
 # wrapper scripts like adb_gdb_content_shell
@@ skipping 622 matching lines @@
           "$NDK_DIR" "$ARCH" "$HOST_OS-x86/bin/i686-android-linux-gcc")
   fi
   if [ -z "$GCC" ]; then
     panic "Cannot find Android NDK toolchain for '$ARCH' architecture. \
 Please verify your NDK installation!"
   fi
   echo "${GCC%%gcc}"
 }
 
 # $1: NDK install path
+get_ndk_host_gdb_client() {
+  local NDK_DIR="$1"
+  local HOST_OS HOST_ARCH
+
+  HOST_OS=$(get_ndk_host_system)
+  HOST_ARCH=$(get_ndk_host_arch)
+  echo "$NDK_DIR/prebuilt/$HOST_OS-$HOST_ARCH/bin/gdb"
+}
+
+# $1: NDK install path
 # $2: target architecture.
 get_ndk_gdbserver () {
   local NDK_DIR="$1"
   local ARCH=$2
   local BINARY
 
   # The location has moved after NDK r8
   BINARY=$NDK_DIR/prebuilt/android-$ARCH/gdbserver/gdbserver
   if [ ! -f "$BINARY" ]; then
     BINARY=$(get_ndk_toolchain_prebuilt "$NDK_DIR" "$ARCH" gdbserver)
@@ skipping 18 matching lines @@
     TOOLCHAIN=$TOOLCHAIN/bin
   fi
   ANDROID_TOOLCHAIN=$TOOLCHAIN
 fi
 
 # Cosmetic: Remove trailing directory separator.
 ANDROID_TOOLCHAIN=${ANDROID_TOOLCHAIN%/}
 
 # Find host GDB client binary
 if [ -z "$GDB" ]; then
-  GDB=$(which $ANDROID_TOOLCHAIN/*-$GDBEXEPOSTFIX 2>/dev/null | head -1)
+  GDB=$(get_ndk_host_gdb_client "$ANDROID_NDK_ROOT")
   if [ -z "$GDB" ]; then
     panic "Can't find Android gdb client in your path, check your \
 --toolchain or --gdb path."
   fi
   log "Host gdb client: $GDB"
 fi
 
 # Find gdbserver binary, we will later push it to /data/local/tmp
 # This ensures that both gdbserver and $GDB talk the same binary protocol,
 # otherwise weird problems will appear.
@@ skipping 340 matching lines @@
 
 if [ "$VERBOSE" -gt 0 ]; then
   echo "### START $COMMANDS"
   cat $COMMANDS
   echo "### END $COMMANDS"
 fi
 
 log "Launching gdb client: $GDB $GDB_ARGS -x $COMMANDS"
 $GDB $GDB_ARGS -x $COMMANDS &&
 rm -f "$GDBSERVER_PIDFILE"