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

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=193020

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

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@193040 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 3 insertions, 3 deletions

diff --git a/device/media_transfer_protocol/media_transfer_protocol_manager.cc b/device/media_transfer_protocol/media_transfer_protocol_manager.cc
index bbd13b3..d3fce03 100644
--- a/device/media_transfer_protocol/media_transfer_protocol_manager.cc
+++ b/device/media_transfer_protocol/media_transfer_protocol_manager.cc
@@ -111,7 +111,7 @@ class MediaTransferProtocolManagerImpl : public MediaTransferProtocolManager {
                            const OpenStorageCallback& callback) OVERRIDE {
     DCHECK(thread_checker_.CalledOnValidThread());
     if (!ContainsKey(storage_info_map_, storage_name)) {
-      callback.Run("", true);
+      callback.Run(std::string(), true);
       return;
     }
     open_storage_callbacks_.push(callback);
@@ -333,13 +333,13 @@ class MediaTransferProtocolManagerImpl : public MediaTransferProtocolManager {
       open_storage_callbacks_.front().Run(handle, false);
     } else {
       NOTREACHED();
-      open_storage_callbacks_.front().Run("", true);
+      open_storage_callbacks_.front().Run(std::string(), true);
     }
     open_storage_callbacks_.pop();
   }
 
   void OnOpenStorageError() {
-    open_storage_callbacks_.front().Run("", true);
+    open_storage_callbacks_.front().Run(std::string(), true);
     open_storage_callbacks_.pop();
   }