Android WebView: make sure libwebview target isn't mangled.

The android gyp backend has been updated to introduce an
"android_unmangled_name" target option, which allows the backend to skip
mangling the name of designated targets. Turn this on for libwebview in
order that it's generated as libwebview.so instead of
lib_android_webview_libwebview_gyp.so which was rather confusing.

BUG=

Review URL: https://codereview.chromium.org/11198030

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@162410 0039d316-1c4b-4281-b951-d872f2087c98

android_webview/android_webview.gyp

@@ -9,6 +9,7 @@
     {
       'target_name': 'libwebview',
       'type': 'shared_library',
+      'android_unmangled_name': 1,
       'dependencies': [
         '../chrome/chrome.gyp:browser',
         '../chrome/chrome.gyp:renderer',