Cleanup: Move json.h into rtc namespace.

This should fix the TODO in that header.

BUG=None
TEST=ninja -C out/Debug still compiles everything.
R=tommi@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/47919004

Patch from Thiago Farina <tfarina@chromium.org>.

Cr-Commit-Position: refs/heads/master@{#8921}
diff --git a/talk/examples/peerconnection/client/conductor.cc b/talk/examples/peerconnection/client/conductor.cc
index bf0d6c9..f30516f 100644
--- a/talk/examples/peerconnection/client/conductor.cc
+++ b/talk/examples/peerconnection/client/conductor.cc
@@ -283,7 +283,7 @@
   std::string type;
   std::string json_object;
 
-  GetStringFromJsonObject(jmessage, kSessionDescriptionTypeName, &type);
+  rtc::GetStringFromJsonObject(jmessage, kSessionDescriptionTypeName, &type);
   if (!type.empty()) {
     if (type == "offer-loopback") {
       // This is a loopback call.
@@ -297,7 +297,8 @@
     }
 
     std::string sdp;
-    if (!GetStringFromJsonObject(jmessage, kSessionDescriptionSdpName, &sdp)) {
+    if (!rtc::GetStringFromJsonObject(jmessage, kSessionDescriptionSdpName,
+                                      &sdp)) {
       LOG(WARNING) << "Can't parse received session description message.";
       return;
     }
@@ -319,10 +320,11 @@
     std::string sdp_mid;
     int sdp_mlineindex = 0;
     std::string sdp;
-    if (!GetStringFromJsonObject(jmessage, kCandidateSdpMidName, &sdp_mid) ||
-        !GetIntFromJsonObject(jmessage, kCandidateSdpMlineIndexName,
-                              &sdp_mlineindex) ||
-        !GetStringFromJsonObject(jmessage, kCandidateSdpName, &sdp)) {
+    if (!rtc::GetStringFromJsonObject(jmessage, kCandidateSdpMidName,
+                                      &sdp_mid) ||
+        !rtc::GetIntFromJsonObject(jmessage, kCandidateSdpMlineIndexName,
+                                   &sdp_mlineindex) ||
+        !rtc::GetStringFromJsonObject(jmessage, kCandidateSdpName, &sdp)) {
       LOG(WARNING) << "Can't parse received message.";
       return;
     }