Make base::FilePath move constructor and assignment noexcept.

base/files/file_path.h

Index: base/files/file_path.h
diff --git a/base/files/file_path.h b/base/files/file_path.h
index 02846f689218816b4048ee39dbfeb2e8b32f88d4..0be0ad0b1049e6809574ec5dcd372462cd106d41 100644
--- a/base/files/file_path.h
+++ b/base/files/file_path.h
@@ -184,7 +184,7 @@ class BASE_EXPORT FilePath {
 
   // Constructs FilePath with the contents of |that|, which is left in valid but
   // unspecified state.
-  FilePath(FilePath&& that);
+  FilePath(FilePath&& that) noexcept;
   // Replaces the contents with those of |that|, which is left in valid but
   // unspecified state.
   FilePath& operator=(FilePath&& that);