Replace deps with depsformat in GN tool defs

build/toolchain/nacl/BUILD.gn

Index: build/toolchain/nacl/BUILD.gn
diff --git a/build/toolchain/nacl/BUILD.gn b/build/toolchain/nacl/BUILD.gn
index 362e9124ae9f532af14041f090d0c13d120f4434..8c76f5a969752fabb1e5e27658631c5652a7c389 100644
--- a/build/toolchain/nacl/BUILD.gn
+++ b/build/toolchain/nacl/BUILD.gn
@@ -12,14 +12,14 @@ toolchain("x86_newlib") {
     command = "$cc -MMD -MF \$out.d \$defines \$includes \$cflags \$cflags_c -c \$in -o \$out"
     description = "CC(NaCl x86 Newlib) \$out"
     depfile = "\$out.d"
-    deps = "gcc"
+    depsformat = "gcc"
   }
   tool("cxx") {
     # cflags_pch_cc
     command = "$cxx -MMD -MF \$out.d \$defines \$includes \$cflags \$cflags_cc -c \$in -o \$out"
     description = "CXX(NaCl x86 Newlib) \$out"
     depfile = "\$out.d"
-    deps = "gcc"
+    depsformat = "gcc"
   }
   tool("alink") {
     command = "rm -f \$out && ${toolprefix}ar rcs \$out \$in"