Write mojom and StructTraits for DisplaySnapshot.

ui/display/types/display_mode.cc

Index: ui/display/types/display_mode.cc
diff --git a/ui/display/types/display_mode.cc b/ui/display/types/display_mode.cc
index 6d43caa5638406c5e43a4b7003d0e491db066715..9874f7af8c168be2ab9991d086acf805bf85eacb 100644
--- a/ui/display/types/display_mode.cc
+++ b/ui/display/types/display_mode.cc
@@ -18,10 +18,14 @@ DisplayMode::DisplayMode(const gfx::Size& size,
 
 DisplayMode::~DisplayMode() {}
 
-std::unique_ptr<DisplayMode> DisplayMode::Clone() const {
-  return base::WrapUnique(new DisplayMode(size_,
-                                          is_interlaced_,
-                                          refresh_rate_));
+bool DisplayMode::operator==(const DisplayMode& other) const {
+  return this->size() == other.size() &&
+         this->is_interlaced() == other.is_interlaced() &&
+         this->refresh_rate() == other.refresh_rate();
+}
+
+bool DisplayMode::operator!=(const DisplayMode& other) const {
+  return !operator==(other);
 }
 
 std::string DisplayMode::ToString() const {
@@ -32,6 +36,11 @@ std::string DisplayMode::ToString() const {
                             refresh_rate_);
 }
 
+std::unique_ptr<DisplayMode> DisplayMode::Clone() const {

[kylechar, 2017/02/15 16:48:45]

Please keep the order consistent between header and source files. You moved
Clone() under ToString() for some reason in this patch?

[thanhph, 2017/02/16 11:48:21]

Nice catch. Thanks!

+  return base::WrapUnique(
+      new DisplayMode(size_, is_interlaced_, refresh_rate_));
+}
+
 void PrintTo(const DisplayMode& mode, std::ostream* os) {
   *os << mode.ToString();
 }