Make the navigator.usb attribute accessible only in secure contexts.

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 37 matching lines @@
   if (!executionContext)
     return;
   v8::Isolate* isolate = scriptState->isolate();
   const DOMWrapperWorld& world = scriptState->world();
   if (wrapperTypeInfo == &V8Navigator::wrapperTypeInfo) {
     if (OriginTrials::webShareEnabled(executionContext)) {
       V8NavigatorPartial::installWebShare(isolate, world,
                                           v8::Local<v8::Object>(),
                                           prototypeObject, interfaceObject);
     }
-    if (OriginTrials::webUSBEnabled(executionContext)) {
+    // Mimics the [SecureContext] extended attribute.
+    if (OriginTrials::webUSBEnabled(executionContext) &&
+        executionContext->isSecureContext()) {

[chasej, 2017/02/22 19:34:18]

The check for secure context is redundant. Origin trials are already
limited to secure contexts. So, the OriginTrials::webUSBEnabled()
method will return false if it is not a secure context.

       V8NavigatorPartial::installWebUSB(isolate, world, v8::Local<v8::Object>(),
                                         prototypeObject, interfaceObject);
     }
     if (OriginTrials::webVREnabled(executionContext)) {
       V8NavigatorPartial::installWebVR(isolate, world, v8::Local<v8::Object>(),
                                        prototypeObject, interfaceObject);
     }
   } else if (wrapperTypeInfo == &V8Window::wrapperTypeInfo) {
     v8::Local<v8::Object> instanceObject = scriptState->context()->Global();
     if (OriginTrials::imageCaptureEnabled(executionContext)) {
       V8WindowPartial::installImageCapture(isolate, world, instanceObject,
                                            prototypeObject, interfaceObject);
     }
-    if (OriginTrials::webUSBEnabled(executionContext)) {
+    // Mimics the [SecureContext] extended attribute.
+    if (OriginTrials::webUSBEnabled(executionContext) &&
+        executionContext->isSecureContext()) {

[chasej, 2017/02/22 19:34:18]

Ditto.

       V8WindowPartial::installWebUSB(isolate, world, instanceObject,
                                      prototypeObject, interfaceObject);
     }
     if (OriginTrials::webVREnabled(executionContext)) {
       V8WindowPartial::installWebVR(isolate, world, instanceObject,
                                     prototypeObject, interfaceObject);
     }
     if (OriginTrials::gamepadExtensionsEnabled(executionContext)) {
       V8WindowPartial::installGamepadExtensions(
           isolate, world, instanceObject, prototypeObject, interfaceObject);
@@ skipping 167 matching lines @@
 void registerInstallConditionalFeaturesForModules() {
   s_originalInstallConditionalFeaturesFunction =
       setInstallConditionalFeaturesFunction(
           &installConditionalFeaturesForModules);
   s_originalInstallPendingConditionalFeatureFunction =
       setInstallPendingConditionalFeatureFunction(
           &installPendingConditionalFeatureForModules);
 }
 
 }  // namespace blink