Mojo C++ bindings: custom type mapping of map

This CL:
- introduces map_traits which is similar to struct_traits;
- adds specialization for mojo::Map and std::map;
- changes the ArraySerializer interface so that it can be re-used by map key/value serialization.

BUG=577686

Review-Url: https://codereview.chromium.org/2014403002
Cr-Commit-Position: refs/heads/master@{#396862}


CrOS-Libchrome-Original-Commit: 507ce12625f5a76456ca3f7c844aa65d025aa0b2
22 files changed
tree: f9dc845ff1fa175641d80f0e24f3293c07213ce7
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/