GN build improvements.

Fixes a TODO about private symbols on GCC.

Moves many third party BUILD.gn files from the secondary tree to the main one.

Fixes the dependencies on Linux so "gn check" passes again.

BUG=367595
R=scottmg@chromium.org

Previous review: https://codereview.chromium.org/256153003/

Review URL: https://codereview.chromium.org/264463002

Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 71d94dfce9c1989595d60e2737e05420cf6a5d5e
diff --git a/BUILD.gn b/BUILD.gn
new file mode 100644
index 0000000..323ff86
--- /dev/null
+++ b/BUILD.gn
@@ -0,0 +1,102 @@
+# Copyright (c) 2013 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.
+
+config("zlib_config") {
+  include_dirs = [ "." ]
+}
+
+static_library("zlib") {
+  if (!is_win) {
+    # Don't stomp on "libzlib" on other platforms.
+    output_name = "chrome_zlib"
+  }
+
+  sources = [
+    "adler32.c",
+    "compress.c",
+    "crc32.c",
+    "crc32.h",
+    "deflate.c",
+    "deflate.h",
+    "gzclose.c",
+    "gzguts.h",
+    "gzlib.c",
+    "gzread.c",
+    "gzwrite.c",
+    "infback.c",
+    "inffast.c",
+    "inffast.h",
+    "inffixed.h",
+    "inflate.c",
+    "inflate.h",
+    "inftrees.c",
+    "inftrees.h",
+    "mozzconf.h",
+    "trees.c",
+    "trees.h",
+    "uncompr.c",
+    "zconf.h",
+    "zlib.h",
+    "zutil.c",
+    "zutil.h",
+  ]
+
+  configs -= [ "//build/config/compiler:chromium_code" ]
+  configs += [ "//build/config/compiler:no_chromium_code" ]
+
+  direct_dependent_configs = [ ":zlib_config" ]
+}
+
+static_library("minizip") {
+  sources = [
+    "contrib/minizip/ioapi.c",
+    "contrib/minizip/ioapi.h",
+    "contrib/minizip/iowin32.c",
+    "contrib/minizip/iowin32.h",
+    "contrib/minizip/unzip.c",
+    "contrib/minizip/unzip.h",
+    "contrib/minizip/zip.c",
+    "contrib/minizip/zip.h",
+  ]
+
+  if (!is_win) {
+    sources -= [
+      "contrib/minizip/iowin32.c",
+      "contrib/minizip/iowin32.h",
+    ]
+  }
+  if (is_mac || is_ios || is_android) {
+    # Mac, Android and the BSDs don't have fopen64, ftello64, or fseeko64. We
+    # use fopen, ftell, and fseek instead on these systems.
+    defines = [ "USE_FILE32API" ]
+  }
+
+  if (is_clang) {
+    # zlib uses `if ((a == b))` for some reason.
+    cflags = [ "-Wno-parentheses-equality" ]
+  }
+
+  deps = [ ":zlib" ]
+
+  configs -= [ "//build/config/compiler:chromium_code" ]
+  configs += [ "//build/config/compiler:no_chromium_code" ]
+  direct_dependent_configs = [ ":zlib_config" ]
+}
+
+if (!is_android) {
+  static_library("zip") {
+    sources = [
+      "google/zip.cc",
+      "google/zip.h",
+      "google/zip_internal.cc",
+      "google/zip_internal.h",
+      "google/zip_reader.cc",
+      "google/zip_reader.h",
+    ]
+    deps = [
+      ":minizip",
+      "//base",
+    ]
+  }
+}