Add SetCustomSavePath API to Nearby Connections

Custom Save Path is the number 1 requested feature from our Windows NS dogfooders program (https://docs.google.com/document/d/1EXQIANtujlTAA3AW7Ol3eSk6lO-1AATMJcARVUre1Bs/edit?usp=sharing&resourcekey=0-Z6V0m71wayqeTwf_pFEyaA). Therefore, we are planning to support this for Windows, but this requires adding an additional API to platform.h which requires adding this stub.

The relevant CLs are:
a) https://critique.corp.google.com/cl/482542038
b) https://critique.corp.google.com/cl/480953162
c) https://critique.corp.google.com/cl/483434698
d) https://critique.corp.google.com/cl/483437861
e) https://critique.corp.google.com/cl/482359860

Test: http://recall/-/enjTV9n45jvDulchchroVI/qtbwmkvneNrCKeRyJmc7P
Bug: b/253018423
Change-Id: Id75bb0aacc6d2cc43620061dc8f815c0bbc35294
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3990952
Reviewed-by: Crisrael Lucero <crisrael@google.com>
Reviewed-by: Ryan Hansberry <hansberry@chromium.org>
Commit-Queue: Aaron Yu <aaronyujiaze@google.com>
Cr-Commit-Position: refs/heads/main@{#1078888}

DEPS

@@ -434,7 +434,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling nearby
   # and whatever else without interference from each other.
-  'nearby_revision': '2273c87b575e4c756d4d9394e1e37c84717baefa',
+  'nearby_revision': '49af1a96b6c135505614b5fbb269b48e525943bf',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling securemessage
   # and whatever else without interference from each other.

chrome/services/sharing/nearby/platform.cc

@@ -57,14 +57,24 @@ int GetCurrentTid() {
   return 0;
 }
 
+std::string ImplementationPlatform::GetCustomSavePath(
+    const std::string& parent_folder,
+    const std::string& file_name) {
+  // This should return the <saved_custom_path>/file_name. For now we will
+  // just return an empty string, since chrome doesn't call this yet.
+  // TODO(b/223710122): Eventually chrome should implement this method.
+  NOTIMPLEMENTED();
+  return std::string();
+}
+
 std::string ImplementationPlatform::GetDownloadPath(
-    absl::string_view parent_folder,
+    const std::string& parent_folder,
-    absl::string_view file_name) {
+    const std::string& file_name) {
   // This should return the <download_path>/parent_folder/file_name. For now we
   // will just return an empty string, since chrome doesn't call this yet.
   // TODO(b/223710122): Eventually chrome should implement this method.
   NOTIMPLEMENTED();
-  return std::string("");
+  return std::string();
 }
 
 OSName ImplementationPlatform::GetCurrentOS() {
@@ -134,7 +144,7 @@ std::unique_ptr<InputFile> ImplementationPlatform::CreateInputFile(
 }
 
 std::unique_ptr<InputFile> ImplementationPlatform::CreateInputFile(
-    absl::string_view file_path,
+    const std::string& file_path,
     size_t size) {
   // This constructor is not called by Chrome. Returning nullptr, just in case.
   // TODO(b/223710122): Eventually chrome should implement and use this
@@ -152,7 +162,7 @@ std::unique_ptr<OutputFile> ImplementationPlatform::CreateOutputFile(
 }
 
 std::unique_ptr<OutputFile> ImplementationPlatform::CreateOutputFile(
-    absl::string_view file_path) {
+    const std::string& file_path) {
   // This constructor is not called by Chrome. Returning nullptr, just in case.
   // TODO(b/223710122): Eventually chrome should implement and use this
   // constructor exclusively.

third_party/nearby/README.chromium

@@ -1,7 +1,7 @@
 Name: Nearby Connections Library
 Short Name: Nearby
 URL: https://github.com/google/nearby
-Version: 2273c87b575e4c756d4d9394e1e37c84717baefa
+Version: 49af1a96b6c135505614b5fbb269b48e525943bf
 License: Apache 2.0
 License File: LICENSE
 Security Critical: yes