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

1 files changed, 7 insertions, 6 deletions

diff --git a/chrome/test/chromedriver/commands_unittest.cc b/chrome/test/chromedriver/commands_unittest.cc
index dabe0e2..dcfc06f 100644
--- a/chrome/test/chromedriver/commands_unittest.cc
+++ b/chrome/test/chromedriver/commands_unittest.cc
@@ -28,7 +28,8 @@ TEST(CommandsTest, GetStatus) {
   base::DictionaryValue params;
   scoped_ptr<base::Value> value;
   std::string session_id;
-  ASSERT_EQ(kOk, ExecuteGetStatus(params, "", &value, &session_id).code());
+  ASSERT_EQ(
+      kOk, ExecuteGetStatus(params, std::string(), &value, &session_id).code());
   base::DictionaryValue* dict;
   ASSERT_TRUE(value->GetAsDictionary(&dict));
   base::Value* unused;
@@ -72,7 +73,7 @@ TEST(CommandsTest, QuitAll) {
   scoped_ptr<base::Value> value;
   std::string session_id;
   Status status =
-      ExecuteQuitAll(cmd, &map, params, "", &value, &session_id);
+      ExecuteQuitAll(cmd, &map, params, std::string(), &value, &session_id);
   ASSERT_EQ(kOk, status.code());
   ASSERT_FALSE(value.get());
   ASSERT_EQ(2, count);
@@ -243,7 +244,7 @@ TEST(CommandsTest, SuccessfulFindElement) {
   FindElementWebView web_view(true, kElementExistsQueryTwice);
   Session session("id");
   session.implicit_wait = 1000;
-  session.SwitchToSubFrame("frame_id1", "");
+  session.SwitchToSubFrame("frame_id1", std::string());
   base::DictionaryValue params;
   params.SetString("using", "id");
   params.SetString("value", "a");
@@ -272,7 +273,7 @@ TEST(CommandsTest, SuccessfulFindElements) {
   FindElementWebView web_view(false, kElementExistsQueryTwice);
   Session session("id");
   session.implicit_wait = 1000;
-  session.SwitchToSubFrame("frame_id2", "");
+  session.SwitchToSubFrame("frame_id2", std::string());
   base::DictionaryValue params;
   params.SetString("using", "name");
   params.SetString("value", "b");
@@ -306,7 +307,7 @@ TEST(CommandsTest, SuccessfulFindChildElement) {
   FindElementWebView web_view(true, kElementExistsQueryTwice);
   Session session("id");
   session.implicit_wait = 1000;
-  session.SwitchToSubFrame("frame_id3", "");
+  session.SwitchToSubFrame("frame_id3", std::string());
   base::DictionaryValue params;
   params.SetString("using", "tag name");
   params.SetString("value", "div");
@@ -344,7 +345,7 @@ TEST(CommandsTest, SuccessfulFindChildElements) {
   FindElementWebView web_view(false, kElementExistsQueryTwice);
   Session session("id");
   session.implicit_wait = 1000;
-  session.SwitchToSubFrame("frame_id4", "");
+  session.SwitchToSubFrame("frame_id4", std::string());
   base::DictionaryValue params;
   params.SetString("using", "class name");
   params.SetString("value", "c");