Rewrite std::string("") to std::string(), Linux edition.

This patch was generated by running the empty_string clang tool
across the Chromium Linux compilation database. Implicitly or
explicitly constructing std::string() with a "" argument is
inefficient as the caller needs to emit extra instructions to
pass an argument, and the constructor needlessly copies a byte
into internal storage. Rewriting these instances to simply call
the default constructor appears to save ~14-18 kilobytes on an
optimized release build.

BUG=none

Review URL: https://codereview.chromium.org/13145003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@193020 0039d316-1c4b-4281-b951-d872f2087c98


CrOS-Libchrome-Original-Commit: e59558b78e8c6a1b0bd916a724724b638c3c91b6
31 files changed
tree: 3d0408d6375c71b23ece2ddaa9aa2d0826bda395
  1. base/
  2. build/
  3. dbus/
  4. ipc/
  5. testing/
  6. third_party/