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

chrome/common/extensions/extension_set_unittest.cc

Index: chrome/common/extensions/extension_set_unittest.cc
diff --git a/chrome/common/extensions/extension_set_unittest.cc b/chrome/common/extensions/extension_set_unittest.cc
index 1703966cfc8c9f324e803b741241ee26db4d6225..c27b0a9cd8e7f478fc4aeed0fe040e088ed00463 100644
--- a/chrome/common/extensions/extension_set_unittest.cc
+++ b/chrome/common/extensions/extension_set_unittest.cc
@@ -59,7 +59,8 @@ TEST(ExtensionSetTest, ExtensionSet) {
   scoped_refptr<Extension> ext3(CreateTestExtension(
       "b", "http://dev.chromium.org/", "http://dev.chromium.org/"));
 
-  scoped_refptr<Extension> ext4(CreateTestExtension("c", "", ""));
+  scoped_refptr<Extension> ext4(
+      CreateTestExtension("c", std::string(), std::string()));
 
   ASSERT_TRUE(ext1 && ext2 && ext3 && ext4);
 
@@ -118,8 +119,10 @@ TEST(ExtensionSetTest, ExtensionSet) {
   EXPECT_FALSE(extensions.GetByID(ext2->id()));
 
   // Make a union of a set with 3 more extensions (only 2 are new).
-  scoped_refptr<Extension> ext5(CreateTestExtension("d", "", ""));
-  scoped_refptr<Extension> ext6(CreateTestExtension("e", "", ""));
+  scoped_refptr<Extension> ext5(
+      CreateTestExtension("d", std::string(), std::string()));
+  scoped_refptr<Extension> ext6(
+      CreateTestExtension("e", std::string(), std::string()));
   ASSERT_TRUE(ext5 && ext6);
 
   scoped_ptr<ExtensionSet> to_add(new ExtensionSet());