Preparation for new Promise-based RTCPeerConnection.getStats.

third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.cpp

Index: third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.cpp
diff --git a/third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.cpp b/third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.cpp
index f2e997a1fe24c9608d265375d8e6e6a9f97c7ca9..bb815640d560d9ce38e2ed3e7d21e615574910d4 100644
--- a/third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.cpp
+++ b/third_party/WebKit/Source/modules/peerconnection/RTCPeerConnection.cpp
@@ -40,7 +40,9 @@
 #include "bindings/core/v8/ScriptValue.h"
 #include "bindings/core/v8/V8ThrowException.h"
 #include "bindings/modules/v8/RTCIceCandidateInitOrRTCIceCandidate.h"
+#include "bindings/modules/v8/V8MediaStreamTrack.h"
 #include "bindings/modules/v8/V8RTCCertificate.h"
+#include "bindings/modules/v8/V8RTCStatsCallback.h"
 #include "core/dom/DOMException.h"
 #include "core/dom/DOMTimeStamp.h"
 #include "core/dom/Document.h"
@@ -71,6 +73,7 @@
 #include "modules/peerconnection/RTCStatsRequestImpl.h"
 #include "modules/peerconnection/RTCVoidRequestImpl.h"
 #include "modules/peerconnection/RTCVoidRequestPromiseImpl.h"
+#include "platform/RuntimeEnabledFeatures.h"
 #include "platform/peerconnection/RTCAnswerOptionsPlatform.h"
 #include "platform/peerconnection/RTCConfiguration.h"
 #include "platform/peerconnection/RTCOfferOptionsPlatform.h"
@@ -371,6 +374,20 @@ RTCOfferOptionsPlatform* parseOfferOptions(const Dictionary& options)
     return rtcOfferOptions;
 }
 
+RTCStatsCallback* ValueToRTCStatsCallback(ScriptState* scriptState, const v8::Local<v8::Value>& value)
+{
+    if (!value->IsObject())
+        return nullptr;
+    v8::Local<v8::Object> object = value->ToObject();
+    if (!object->IsCallable())
+        return nullptr;
+    v8::Local<v8::Function> function = v8::Local<v8::Function>::Cast(object);
+    // |function| should have one argument. If called and it doesn't have one it
+    // is still invoked but without the |RTCLegacyStatsReport|. If it has more
+    // than one argument it is invoked with the subsequent arguments undefined.

[hta - Chromium, 2016/07/19 09:56:48]

Is this just a description of how v8::Function works, or is there something
special about this particular usage of v8::Function?

If it's just general, I suggest removing it.

[hbos_chromium, 2016/07/19 13:59:35]

Done.

+    return V8RTCStatsCallback::create(function, scriptState);
+}
+
 } // namespace
 
 RTCPeerConnection::EventWrapper::EventWrapper(
@@ -948,12 +965,73 @@ MediaStream* RTCPeerConnection::getStreamById(const String& streamId)
     return 0;
 }
 
-void RTCPeerConnection::getStats(ExecutionContext* context, RTCStatsCallback* successCallback, MediaStreamTrack* selector)
+ScriptPromise RTCPeerConnection::getStats(ScriptState* scriptState, ScriptValue value)
 {
+    v8::Local<v8::Value> v8Value = value.v8Value();
+    if (v8Value->IsUndefined() || v8Value->IsNull()) {
+        // Dispatch to "getStats(optional MediaStreamTrack?)".
+        return getStats(scriptState, static_cast<MediaStreamTrack*>(nullptr));
+    }
+    if (v8Value->IsObject()) {
+        // Is |v8Value| a |MediaStreamTrack|?
+        MediaStreamTrack* selector = V8MediaStreamTrack::toImplWithTypeCheck(scriptState->isolate(), v8Value);
+        if (selector) {
+            // Dispatch to "getStats(optional MediaStreamTrack?)".
+            return getStats(scriptState, selector);
+        }
+
+        // [RTCStatsCallback| is either a function or an object that contains a |handleEvent| function.
+        // Is |v8Value| a valid callback function?
+        RTCStatsCallback* callback = ValueToRTCStatsCallback(scriptState, v8Value);
+        if (!callback) {
+            // Is "value.handleEvent" a valid callback function?
+            v8::Local<v8::Object> object = v8Value->ToObject(scriptState->context()).ToLocalChecked();
+            v8::MaybeLocal<v8::Value> handleEvent = object->Get(
+                scriptState->context(),
+                v8::String::NewFromUtf8(scriptState->isolate(), "handleEvent"));
+            if (!handleEvent.IsEmpty())
+                callback = ValueToRTCStatsCallback(scriptState, handleEvent.ToLocalChecked());
+        }
+        if (callback) {
+            // Dispatch to "getStats(RTCStatsCallback, MediaStreamTrack?)".
+            return getStats(scriptState, callback, nullptr);
+        }
+    }
+
+    // Invalid parameter, |value| is not compatible with |MediaStreamTrack| or |RTCStatsCallback|.
+    ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
+    ScriptPromise promise = resolver->promise();
+    resolver->reject();

[hta - Chromium, 2016/07/19 09:56:48]

Where do we set the error to be returned in this case?

[hbos_chromium, 2016/07/19 13:59:35]

This error was undefined. I added an error and updated other rejection code to
use rejectWithDOMException instead.

+    return promise;
+}
+
+ScriptPromise RTCPeerConnection::getStats(ScriptState* scriptState, RTCStatsCallback* successCallback, MediaStreamTrack* selector)
+{
+    ExecutionContext* context = scriptState->getExecutionContext();
+    ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
+    ScriptPromise promise = resolver->promise();
+
     UseCounter::count(context, UseCounter::RTCPeerConnectionGetStatsLegacyNonCompliant);
     RTCStatsRequest* statsRequest = RTCStatsRequestImpl::create(getExecutionContext(), this, successCallback, selector);
     // FIXME: Add passing selector as part of the statsRequest.
     m_peerHandler->getStats(statsRequest);
+
+    resolver->resolve();
+    return promise;
+}
+
+ScriptPromise RTCPeerConnection::getStats(ScriptState* scriptState, MediaStreamTrack* selector)
+{
+    ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
+    ScriptPromise promise = resolver->promise();
+    if (!RuntimeEnabledFeatures::rTCPeerConnectionNewGetStatsEnabled()) {
+        resolver->reject(ExceptionMessages::argumentNullOrIncorrectType(1, "successCallback"));
+        return promise;
+    }
+
+    // TODO(hbos): Implement new |getStats| function.
+    resolver->reject(DOMException::create(NotSupportedError, "getStats(optional MediaStreamTrack?) has not been implemented yet."));
+    return promise;
 }
 
 RTCDataChannel* RTCPeerConnection::createDataChannel(String label, const Dictionary& options, ExceptionState& exceptionState)