Introduce CryptAuthClient, a class capable of performing all CryptAuth APIs.

components/proximity_auth/switches.cc

Index: components/proximity_auth/switches.cc
diff --git a/components/proximity_auth/switches.cc b/components/proximity_auth/switches.cc
index ba5aab7f52ba4a2486c9c675501b1c9345d39160..cb1acfe5defbd71b9c984e1c4096db519b343111 100644
--- a/components/proximity_auth/switches.cc
+++ b/components/proximity_auth/switches.cc
@@ -7,6 +7,10 @@
 namespace proximity_auth {
 namespace switches {
 
+// Overrides the default URL for Google APIs (https://www.googleapis.com) used
+// by CryptAuth.
+const char kCryptAuthGoogleApisUrl[] = "cryptauth-google-apis-url";

[Ilya Sherman, 2014/11/18 22:30:44]

Is this just for testing use?  Do we need it long-term, or is it something we
need temporarily?  If just temporarily, please annotate with a TODO to remove
it.

[Tim Song, 2014/12/03 01:18:24]

This flag is used in development so we can point to the sandbox/localhost
version of CryptAuth.

Renamed to kCryptAuthHTTPHost.

+
 // Enables close proximity detection. This allows the user to set a setting to
 // require very close proximity between the remote device and the local device
 // in order to unlock the local device, which trades off convenience for