Move constructor for base::FilePath

R=danakj@chromium.org
BUG=670043

Review-Url: https://codereview.chromium.org/2627713002
Cr-Commit-Position: refs/heads/master@{#443129}

base/files/file_path.cc

@@ -174,6 +174,7 @@ FilePath::FilePath() {
 
 FilePath::FilePath(const FilePath& that) : path_(that.path_) {
 }
+FilePath::FilePath(FilePath&& that) = default;
 
 FilePath::FilePath(StringPieceType path) {
   path.CopyToString(&path_);
@@ -190,6 +191,8 @@ FilePath& FilePath::operator=(const FilePath& that) {
   return *this;
 }
 
+FilePath& FilePath::operator=(FilePath&& that) = default;
+
 bool FilePath::operator==(const FilePath& that) const {
 #if defined(FILE_PATH_USES_DRIVE_LETTERS)
   return EqualDriveLetterCaseInsensitive(this->path_, that.path_);

base/files/file_path.h

@@ -182,6 +182,13 @@ class BASE_EXPORT FilePath {
   ~FilePath();
   FilePath& operator=(const FilePath& that);
 
+  // Constructs FilePath with the contents of |that|, which is left in valid but
+  // unspecified state.
+  FilePath(FilePath&& that);
+  // Replaces the contents with those of |that|, which is left in valid but
+  // unspecified state.
+  FilePath& operator=(FilePath&& that);
+
   bool operator==(const FilePath& that) const;
 
   bool operator!=(const FilePath& that) const;