Moves manifest parsing to a new class, Reader.

mojo/shell/public/cpp/lib/capabilities.cc

Index: mojo/shell/public/cpp/lib/capabilities.cc
diff --git a/mojo/shell/public/cpp/lib/capabilities.cc b/mojo/shell/public/cpp/lib/capabilities.cc
index cc3fc1801941e4247f72af77f56bbacd268a16b7..add91505cbcf9d21056c8c8cfceddb71d96583e6 100644
--- a/mojo/shell/public/cpp/lib/capabilities.cc
+++ b/mojo/shell/public/cpp/lib/capabilities.cc
@@ -13,6 +13,11 @@ bool CapabilityRequest::operator==(const CapabilityRequest& other) const {
   return other.classes == classes && other.interfaces == interfaces;
 }
 
+bool CapabilityRequest::operator<(const CapabilityRequest& other) const {
+  return std::tie(classes, interfaces) <
+      std::tie(other.classes, other.interfaces);
+}
+
 CapabilitySpec::CapabilitySpec() {}
 CapabilitySpec::~CapabilitySpec() {}
 
@@ -20,6 +25,11 @@ bool CapabilitySpec::operator==(const CapabilitySpec& other) const {
   return other.provided == provided && other.required == required;
 }
 
+bool CapabilitySpec::operator<(const CapabilitySpec& other) const {
+  return std::tie(provided, required) <
+      std::tie(other.provided, other.required);
+}
+
 // static
 shell::mojom::CapabilitySpecPtr
 TypeConverter<shell::mojom::CapabilitySpecPtr, CapabilitySpec>::Convert(