FileSystem: Add move constructor/operator for FileSystemURL.

This is not strictly required for issue 797292 (filesystem:
support with network service), but it should make that implementation
slightly more efficient and better to land in its own CL.

Bug: 797292
Change-Id: Ia6a20ded0f0c414d632530805bc3ae3eb3053328
Reviewed-on: https://chromium-review.googlesource.com/960922Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Commit-Queue: Chris Mumford <cmumford@chromium.org>
Cr-Commit-Position: refs/heads/master@{#543380}

storage/browser/fileapi/file_system_url.cc

@@ -26,6 +26,12 @@ FileSystemURL::FileSystemURL()
 
 FileSystemURL::FileSystemURL(const FileSystemURL& other) = default;
 
+FileSystemURL::FileSystemURL(FileSystemURL&& other) noexcept = default;
+
+FileSystemURL& FileSystemURL::operator=(FileSystemURL&& rhs) = default;
+
+FileSystemURL& FileSystemURL::operator=(const FileSystemURL& rhs) = default;
+
 // static
 FileSystemURL FileSystemURL::CreateForTest(const GURL& url) {
   return FileSystemURL(url);

storage/browser/fileapi/file_system_url.h

@@ -79,8 +79,17 @@ class STORAGE_EXPORT FileSystemURL {
  public:
   FileSystemURL();
   FileSystemURL(const FileSystemURL& other);
+  // Constructs FileSystemURL with the contents of |other|, which is left in
+  // valid but unspecified state.
+  FileSystemURL(FileSystemURL&& other) noexcept;
   ~FileSystemURL();
 
+  // Replaces the contents with those of |rhs|, which is left in valid but
+  // unspecified state.
+  FileSystemURL& operator=(FileSystemURL&& rhs);
+
+  FileSystemURL& operator=(const FileSystemURL& rhs);
+
   // Methods for creating FileSystemURL without attempting to crack them.
   // Should be used only in tests.
   static FileSystemURL CreateForTest(const GURL& url);

storage/browser/fileapi/file_system_url_unittest.cc

@@ -6,6 +6,8 @@
 
 #include <stddef.h>
 
+#include <utility>
+
 #include "base/files/file_path.h"
 #include "base/macros.h"
 #include "storage/common/fileapi/file_system_types.h"
@@ -221,4 +223,29 @@ TEST(FileSystemURLTest, IsInSameFileSystem) {
   EXPECT_FALSE(url_foo_temp_a.IsInSameFileSystem(url_bar_perm_a));
 }
 
+TEST(FileSystemURLTest, ValidAfterMoves) {
+  // Move constructor.
+  {
+    FileSystemURL original = FileSystemURL::CreateForTest(
+        GURL("http://foo"), kFileSystemTypeTemporary,
+        base::FilePath::FromUTF8Unsafe("a"));
+    EXPECT_TRUE(original.is_valid());
+    FileSystemURL new_url(std::move(original));
+    EXPECT_TRUE(new_url.is_valid());
+    EXPECT_TRUE(original.is_valid());
+  }
+
+  // Move operator.
+  {
+    FileSystemURL original = FileSystemURL::CreateForTest(
+        GURL("http://foo"), kFileSystemTypeTemporary,
+        base::FilePath::FromUTF8Unsafe("a"));
+    EXPECT_TRUE(original.is_valid());
+    FileSystemURL new_url;
+    new_url = std::move(std::move(original));
+    EXPECT_TRUE(new_url.is_valid());
+    EXPECT_TRUE(original.is_valid());
+  }
+}
+
 }  // namespace content