Add chrome perf tests and sniffer to GN build.

build/config/linux/pkg_config.gni

 # 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.
 
 import("//build/config/sysroot.gni")
 
 # Defines a config specifying the result of running pkg-config for the given
 # packages. Put the package names you want to query in the "packages" variable
 # inside the template invocation.
 #
@@ skipping 15 matching lines @@
 
 declare_args() {
   # A pkg-config wrapper to call instead of trying to find and call the right
   # pkg-config directly. Wrappers like this are common in cross-compilation
   # environments.
   # Leaving it blank defaults to searching PATH for 'pkg-config' and relying on
   # the sysroot mechanism to find the right .pc files.
   pkg_config = ""
 }
 
+pkg_config_script = "//build/config/linux/pkg-config.py"
+
+# Define the args we pass to the pkg-config script for other build files that
+# need to invoke it manually.
+if (sysroot != "") {
+  # Pass the sysroot if we're using one (it requires the CPU arch also).
+  pkg_config_args = ["-s", sysroot, "-a", cpu_arch]
+} else if (pkg_config != "") {
+  pkg_config_args = ["-p", pkg_config]
+} else {
+  pkg_config_args = []
+}
+
 template("pkg_config") {
   assert(defined(invoker.packages),
         "Variable |packages| must be defined to be a list in pkg_config.")
   config(target_name) {
-    if (sysroot != "") {
-      # Pass the sysroot if we're using one (it requires the CPU arch also).
-      args = ["-s", sysroot, "-a", cpu_arch] + invoker.packages
-    } else if (pkg_config != "") {
-      args = ["-p", pkg_config] + invoker.packages
-    } else {
-      args = invoker.packages
-    }
-
+    args = pkg_config_args + invoker.packages
     if (defined(invoker.extra_args)) {
       args += invoker.extra_args
     }
 
-    pkgresult = exec_script("//build/config/linux/pkg-config.py",
-                            args, "value")
+    pkgresult = exec_script(pkg_config_script, args, "value")
     include_dirs = pkgresult[0]
     cflags = pkgresult[1]
 
     if (!defined(invoker.ignore_libs) || !invoker.ignore_libs) {
       libs = pkgresult[2]
       lib_dirs = pkgresult[3]
       ldflags = pkgresult[4]
     }
 
     if (defined(invoker.defines)) {
       defines = invoker.defines
     }
     if (defined(invoker.visibility)) {
       visibility = invoker.visibility
     }
   }
 }