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

3 files changed, 9 insertions, 9 deletions

diff --git a/chrome/browser/devtools/browser_list_tabcontents_provider.cc b/chrome/browser/devtools/browser_list_tabcontents_provider.cc
index aca4bac..2edc6bf 100644
--- a/chrome/browser/devtools/browser_list_tabcontents_provider.cc
+++ b/chrome/browser/devtools/browser_list_tabcontents_provider.cc
@@ -116,19 +116,19 @@ std::string BrowserListTabContentsProvider::GetViewDescription(
   content::WebContents* web_contents =
       content::WebContents::FromRenderViewHost(rvh);
   if (!web_contents)
-    return "";
+    return std::string();
 
   Profile* profile =
       Profile::FromBrowserContext(web_contents->GetBrowserContext());
   if (!profile)
-    return "";
+    return std::string();
 
   extensions::ExtensionHost* extension_host =
       extensions::ExtensionSystem::Get(profile)->process_manager()->
           GetBackgroundHostForExtension(web_contents->GetURL().host());
 
   if (!extension_host || extension_host->host_contents() != web_contents)
-    return "";
+    return std::string();
 
   return extension_host->extension()->name();
 }
diff --git a/chrome/browser/devtools/devtools_file_helper.cc b/chrome/browser/devtools/devtools_file_helper.cc
index d485a52..4aef091 100644
--- a/chrome/browser/devtools/devtools_file_helper.cc
+++ b/chrome/browser/devtools/devtools_file_helper.cc
@@ -77,7 +77,7 @@ class SelectFileDialog : public ui::SelectFileDialog::Listener,
                                     default_path,
                                     NULL,
                                     0,
-                                    FILE_PATH_LITERAL(""),
+                                    FILE_PATH_LITERAL(std::string()),
                                     NULL,
                                     NULL);
   }
@@ -346,7 +346,7 @@ void DevToolsFileHelper::AddValidatedFileSystem(
                                                  file_system_id,
                                                  registered_name,
                                                  file_system_path);
-  callback.Run("", filesystem);
+  callback.Run(std::string(), filesystem);
 }
 
 void DevToolsFileHelper::RequestFileSystems(
diff --git a/chrome/browser/devtools/devtools_sanity_browsertest.cc b/chrome/browser/devtools/devtools_sanity_browsertest.cc
index 6a8b30c..4f832f7 100644
--- a/chrome/browser/devtools/devtools_sanity_browsertest.cc
+++ b/chrome/browser/devtools/devtools_sanity_browsertest.cc
@@ -441,7 +441,7 @@ IN_PROC_BROWSER_TEST_F(
 IN_PROC_BROWSER_TEST_F(DevToolsExtensionTest,
                        TestDevToolsExtensionAPI) {
   LoadExtension("devtools_extension");
-  RunTest("waitForTestResultsInConsole", "");
+  RunTest("waitForTestResultsInConsole", std::string());
 }
 
 // Tests that chrome.devtools extension can communicate with background page
@@ -449,7 +449,7 @@ IN_PROC_BROWSER_TEST_F(DevToolsExtensionTest,
 IN_PROC_BROWSER_TEST_F(DevToolsExtensionTest,
                        TestDevToolsExtensionMessaging) {
   LoadExtension("devtools_messaging");
-  RunTest("waitForTestResultsInConsole", "");
+  RunTest("waitForTestResultsInConsole", std::string());
 }
 
 // Tests that chrome.experimental.devtools extension is correctly exposed
@@ -457,7 +457,7 @@ IN_PROC_BROWSER_TEST_F(DevToolsExtensionTest,
 IN_PROC_BROWSER_TEST_F(DevToolsExperimentalExtensionTest,
                        TestDevToolsExperimentalExtensionAPI) {
   LoadExtension("devtools_experimental");
-  RunTest("waitForTestResultsInConsole", "");
+  RunTest("waitForTestResultsInConsole", std::string());
 }
 
 // Tests that a content script is in the scripts list.
@@ -478,7 +478,7 @@ IN_PROC_BROWSER_TEST_F(DevToolsExtensionTest,
 
 IN_PROC_BROWSER_TEST_F(DevToolsSanityTest,
                        MAYBE_TestRendererProcessNativeMemorySize) {
-  RunTest("testRendererProcessNativeMemorySize", "");
+  RunTest("testRendererProcessNativeMemorySize", std::string());
 }
 
 // Tests that scripts are not duplicated after Scripts Panel switch.