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

chrome/browser/extensions/api/downloads/downloads_api_unittest.cc

Index: chrome/browser/extensions/api/downloads/downloads_api_unittest.cc
diff --git a/chrome/browser/extensions/api/downloads/downloads_api_unittest.cc b/chrome/browser/extensions/api/downloads/downloads_api_unittest.cc
index 23a11317e2fac79aecdb9ed06b50b8e6fbc54592..e403cd5019b23abe79fefbb9182cdfee97aaf901 100644
--- a/chrome/browser/extensions/api/downloads/downloads_api_unittest.cc
+++ b/chrome/browser/extensions/api/downloads/downloads_api_unittest.cc
@@ -737,7 +737,8 @@ class HTML5FileWriter {
   ~HTML5FileWriter() {
     CHECK(BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, base::Bind(
         &HTML5FileWriter::TearDownURLRequestContext, base::Unretained(this))));
-    events_listener_->WaitFor(profile_, kURLRequestContextToreDown, "");
+    events_listener_->WaitFor(
+        profile_, kURLRequestContextToreDown, std::string());
   }
 
   bool WriteFile() {
@@ -1071,8 +1072,10 @@ IN_PROC_BROWSER_TEST_F(DownloadExtensionTest,
 
   // Simulate an error during icon load by invoking the mock with an empty
   // result string.
-  std::string error = RunFunctionAndReturnError(MockedGetFileIconFunction(
-        download_item->GetTargetFilePath(), IconLoader::NORMAL, ""),
+  std::string error = RunFunctionAndReturnError(
+      MockedGetFileIconFunction(download_item->GetTargetFilePath(),
+                                IconLoader::NORMAL,
+                                std::string()),
       args32);
   EXPECT_STREQ(download_extension_errors::kIconNotFoundError, error.c_str());