url: Add a StringPiece variant to PathForRequest

Some of the GURL methods have StringPiece variant helpers. This patch
adds a helper to GURL::PathForRequest.

Test: expands unittest
Change-Id: I488f5cf0e36861b4f7202719f3ab8997ce77c74a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1900356Reviewed-by: Charlie Harrison <csharrison@chromium.org>
Commit-Queue: David Van Cleve <davidvc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#713007}

url/gurl.cc

@@ -396,14 +396,14 @@ std::string GURL::ExtractFileName() const {
   return ComponentString(file_component);
 }
 
-std::string GURL::PathForRequest() const {
+base::StringPiece GURL::PathForRequestPiece() const {
   DCHECK(parsed_.path.len > 0)
       << "Canonical path for requests should be non-empty";
   if (parsed_.ref.len >= 0) {
     // Clip off the reference when it exists. The reference starts after the
     // #-sign, so we have to subtract one to also remove it.
-    return std::string(spec_, parsed_.path.begin,
-                       parsed_.ref.begin - parsed_.path.begin - 1);
+    return base::StringPiece(&spec_[parsed_.path.begin],
+                             parsed_.ref.begin - parsed_.path.begin - 1);
   }
   // Compute the actual path length, rather than depending on the spec's
   // terminator. If we're an inner_url, our spec continues on into our outer
@@ -412,7 +412,11 @@ std::string GURL::PathForRequest() const {
   if (parsed_.query.is_valid())
     path_len = parsed_.query.end() - parsed_.path.begin;
 
-  return std::string(spec_, parsed_.path.begin, path_len);
+  return base::StringPiece(&spec_[parsed_.path.begin], path_len);
+}
+
+std::string GURL::PathForRequest() const {
+  return PathForRequestPiece().as_string();
 }
 
 std::string GURL::HostNoBrackets() const {

url/gurl.h

@@ -386,6 +386,9 @@ class COMPONENT_EXPORT(URL) GURL {
   // parameter, and query portions of the URL. It is guaranteed to be ASCII.
   std::string PathForRequest() const;
 
+  // Returns the same characters as PathForRequest(), avoiding a copy.
+  base::StringPiece PathForRequestPiece() const;
+
   // Returns the host, excluding the square brackets surrounding IPv6 address
   // literals. This can be useful for passing to getaddrinfo().
   std::string HostNoBrackets() const;

url/gurl_unittest.cc

@@ -539,11 +539,14 @@ TEST(GURLTest, PathForRequest) {
 
   for (size_t i = 0; i < base::size(cases); i++) {
     GURL url(cases[i].input);
-    std::string path_request = url.PathForRequest();
-    EXPECT_EQ(cases[i].expected, path_request);
+    EXPECT_EQ(cases[i].expected, url.PathForRequest());
+    EXPECT_EQ(cases[i].expected, url.PathForRequestPiece());
     EXPECT_EQ(cases[i].inner_expected == NULL, url.inner_url() == NULL);
-    if (url.inner_url() && cases[i].inner_expected)
+    if (url.inner_url() && cases[i].inner_expected) {
       EXPECT_EQ(cases[i].inner_expected, url.inner_url()->PathForRequest());
+      EXPECT_EQ(cases[i].inner_expected,
+                url.inner_url()->PathForRequestPiece());
+    }
   }
 }