On linux, fetch should install the build deps before running gyp

fetch.py

Index: fetch.py
diff --git a/fetch.py b/fetch.py
index aca0f88d60945c16fb49d9d79051e3553a2e6009..0454bd8a36099a2c397fa29d83dbe1303f9e5f87 100755
--- a/fetch.py
+++ b/fetch.py
@@ -114,12 +114,18 @@ class GclientGitCheckout(GclientCheckout, GitCheckout):
 
     # Configure and do the gclient checkout.
     self.run_gclient('config', '--spec', self.spec['gclient_spec'])
-    self.run_gclient('sync')
+    self.run_gclient('sync', '--nohooks')
 
-    # Configure git.
     wd = os.path.join(self.base, self.root)
     if self.dryrun:
       print 'cd %s' % wd
+
+    if sys.platform.startswith('linux'):
+      self.run(('build/install-build-deps.sh',), cwd=wd)
+
+    self.run_gclient('runhooks')
+
+    # Configure git.
     self.run_git(
         'submodule', 'foreach',
         'git config -f $toplevel/.git/config submodule.$name.ignore all',