Allow origin trials to be enabled by script

third_party/WebKit/Source/bindings/modules/v8/ConditionalFeaturesForModules.cpp

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "bindings/modules/v8/ConditionalFeaturesForModules.h"
 
 #include "bindings/core/v8/ScriptState.h"
 #include "bindings/core/v8/V8DedicatedWorkerGlobalScope.h"
 #include "bindings/core/v8/V8Navigator.h"
 #include "bindings/core/v8/V8SharedWorkerGlobalScope.h"
@@ skipping 11 matching lines @@
 #include "bindings/modules/v8/V8WindowPartial.h"
 #include "bindings/modules/v8/V8WorkerNavigatorPartial.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/origin_trials/OriginTrials.h"
 
 namespace blink {
 
 namespace {
 InstallConditionalFeaturesFunction
     s_originalInstallConditionalFeaturesFunction = nullptr;
+InstallConditionalFeaturesIfNeededFunction
+    s_originalInstallConditionalFeaturesIfNeededFunction = nullptr;
+GetAffectedTypesForConditionalFeatureFunction
+    s_originalGetAffectedTypesForConditionalFeatureFunction = nullptr;
 }
 
 void installConditionalFeaturesForModules(
     const WrapperTypeInfo* wrapperTypeInfo,
     const ScriptState* scriptState,
     v8::Local<v8::Object> prototypeObject,
     v8::Local<v8::Function> interfaceObject) {
   // TODO(iclelland): Generate all of this logic at compile-time, based on the
   // configuration of origin trial enabled attibutes and interfaces in IDL
   // files. (crbug.com/615060)
@@ skipping 91 matching lines @@
     }
   } else if (wrapperTypeInfo == &V8GamepadButton::wrapperTypeInfo) {
     if (OriginTrials::gamepadExtensionsEnabled(executionContext)) {
       V8GamepadButton::installGamepadExtensions(
           isolate, world, v8::Local<v8::Object>(), prototypeObject,
           interfaceObject);
     }
   }
 }
 
+bool installConditionalFeaturesIfNeededForModules(
+    const WrapperTypeInfo* wrapperTypeInfo,
+    const ScriptState* scriptState) {
+  (*s_originalInstallConditionalFeaturesIfNeededFunction)(wrapperTypeInfo,
+                                                          scriptState);
+
+  // Only install features here, if the target type has an existing instance

[iclelland, 2017/01/20 14:31:19]

I think rather than instance, you mean prototype/constructor here.

[chasej, 2017/01/25 19:58:20]

This method is gone in the new, simplified approach.

+  V8PerContextData* contextData = scriptState->perContextData();
+  if (wrapperTypeInfo == &V8Navigator::wrapperTypeInfo) {
+    v8::Local<v8::Function> interfaceObject =
+        contextData->constructorForTypeFromCache(wrapperTypeInfo);
+    if (interfaceObject.IsEmpty()) {
+      LOG(INFO) << "No existing instance for type: "
+                << wrapperTypeInfo->interfaceName;
+      return true;
+    }
+    LOG(INFO) << "Found existing instance for type: "
+              << wrapperTypeInfo->interfaceName;
+    v8::Local<v8::Object> prototypeObject =
+        contextData->prototypeForType(wrapperTypeInfo);
+
+    installConditionalFeaturesForModules(wrapperTypeInfo, scriptState,
+                                         prototypeObject, interfaceObject);
+    return true;
+  }
+  return false;
+}
+
+void getAffectedTypesForConditionalFeatureFunctionForModules(
+    const String& feature,
+    HashSet<const WrapperTypeInfo*>* affectedTypes) {
+  (*s_originalGetAffectedTypesForConditionalFeatureFunction)(feature,
+                                                             affectedTypes);
+  if (feature == "ServiceWorkerNavigationPreload") {

[iclelland, 2017/01/20 14:31:19]

Is this method eventually intended to cover all of the trial features which are
handled in installConditionalFeaturesForModules, or is this going to be a
hand-curated list?

[chasej, 2017/01/25 19:58:20]

This method is gone in the new, simplified approach.

+    // affectedTypes->add(&V8Navigator::wrapperTypeInfo);
+    affectedTypes->add(&V8Window::wrapperTypeInfo);
+    return;
+  }
+  if (feature == "WebUSB") {
+    affectedTypes->add(&V8Navigator::wrapperTypeInfo);
+    affectedTypes->add(&V8Window::wrapperTypeInfo);
+    return;
+  }
+}
+
 void registerInstallConditionalFeaturesForModules() {
   s_originalInstallConditionalFeaturesFunction =
       setInstallConditionalFeaturesFunction(
           &installConditionalFeaturesForModules);
+  s_originalInstallConditionalFeaturesIfNeededFunction =
+      setInstallConditionalFeaturesIfNeededFunction(
+          &installConditionalFeaturesIfNeededForModules);
+  s_originalGetAffectedTypesForConditionalFeatureFunction =
+      setGetAffectedTypesForConditionalFeatureFunction(
+          &getAffectedTypesForConditionalFeatureFunctionForModules);
 }
 
 }  // namespace blink