Added StringPiece overloads for base::JoinString.

chrome/browser/webshare/share_service_impl.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/webshare/share_service_impl.h"
 
 #include <algorithm>
 #include <functional>
 #include <utility>
 
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_commands.h"
 #include "chrome/browser/ui/browser_dialogs.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/browser_tabstrip.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 #include "net/base/escape.h"
 
 namespace {
 
 // Determines whether a character is allowed in a URL template placeholder.
 bool IsIdentifier(char c) {
   return base::IsAsciiAlpha(c) || base::IsAsciiDigit(c) || c == '-' || c == '_';
 }
 
-// Joins a std::vector<base::StringPiece> into a single std::string.
-// TODO(constantina): Implement a base::JoinString() that takes StringPieces.
-// i.e. move this to base/strings/string_util.h, and thoroughly test.
-std::string JoinString(const std::vector<base::StringPiece>& pieces) {
-  size_t total_size = 0;
-  for (const auto& piece : pieces) {
-    total_size += piece.size();
-  }
-  std::string joined_pieces;
-  joined_pieces.reserve(total_size);
-
-  for (const auto& piece : pieces) {
-    piece.AppendToString(&joined_pieces);
-  }
-  return joined_pieces;
-}
-
 }  // namespace
 
 // static
 void ShareServiceImpl::Create(blink::mojom::ShareServiceRequest request) {
   mojo::MakeStrongBinding(base::MakeUnique<ShareServiceImpl>(),
                           std::move(request));
 }
 
 // static
 bool ShareServiceImpl::ReplacePlaceholders(base::StringPiece url_template,
@@ skipping 46 matching lines @@
       }
     }
   }
   if (last_saw_open) {
     // Error: Saw open that was never closed.
     return false;
   }
   split_template.push_back(url_template.substr(
       start_index_to_copy, url_template.size() - start_index_to_copy));
 
-  *url_template_filled = JoinString(split_template);
+  *url_template_filled = base::JoinStringPiece(split_template, "");
   return true;
 }
 
 void ShareServiceImpl::ShowPickerDialog(
     const std::vector<std::pair<base::string16, GURL>>& targets,
     const base::Callback<void(base::Optional<std::string>)>& callback) {
   // TODO(mgiuca): Get the browser window as |parent_window|.
 #if defined(OS_LINUX) || defined(OS_WIN)
   chrome::ShowWebShareTargetPickerDialog(nullptr /* parent_window */, targets,
                                          callback);
@@ skipping 57 matching lines @@
   GURL target_url(url_template_filled);
   if (!target_url.is_valid()) {
     callback.Run(base::Optional<std::string>(
         "Error: url of share target is not a valid url."));
     return;
   }
   OpenTargetURL(target_url);
 
   callback.Run(base::nullopt);
 }