Add '-ldl' to Linux targets that use dynamic loader functions.

chrome/chrome_browser.gypi

Index: chrome/chrome_browser.gypi
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 3df5a9fb2f009569567857d18ef4257ce35a2ee9..6a0c6b59410ca4b5d97bca5a5254967b68d2d930 100755
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -2196,6 +2196,12 @@
             '../build/linux/system.gyp:nss',
             '../base/base.gyp:linux_versioninfo',
           ],
+          'link_settings': {
+            'libraries': [
+              # For dlsym() in 'browser/zygote_main_linux.cc'
+              '-ldl',
+            ],
+          },
           'sources!': [
              # Exclude extension shelf for toolstrips.
             'browser/views/extensions/extension_shelf.cc',