Mark URLs with empty schemes as invalid.

url/gurl_unittest.cc

Index: url/gurl_unittest.cc
diff --git a/url/gurl_unittest.cc b/url/gurl_unittest.cc
index 1a0987edcb348f5658e5d58f7fdccb40b9141993..6bfba708b9743e9b270d95cab25aa64884a99bae 100644
--- a/url/gurl_unittest.cc
+++ b/url/gurl_unittest.cc
@@ -232,7 +232,6 @@ TEST(GURLTest, IsValid) {
     "http://user:pass@google.com:12345/path?k=v#fragment",
     "http:/path",
     "http:path",
-    "://google.com",
   };
   for (size_t i = 0; i < arraysize(valid_cases); i++) {
     EXPECT_TRUE(GURL(valid_cases[i]).is_valid())
@@ -244,6 +243,7 @@ TEST(GURLTest, IsValid) {
     "http:://google.com",
     "http//google.com",
     "http://google.com:12three45",
+    "://google.com",
     "path",
   };
   for (size_t i = 0; i < arraysize(invalid_cases); i++) {