[sensors] Add Permission guard to the generic sensor apis.

third_party/WebKit/Source/modules/sensor/Sensor.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 "modules/sensor/Sensor.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/ExceptionCode.h"
 #include "core/dom/ExecutionContextTask.h"
 #include "core/inspector/ConsoleMessage.h"
 #include "device/generic_sensor/public/interfaces/sensor.mojom-blink.h"
 #include "modules/sensor/SensorErrorEvent.h"
 #include "modules/sensor/SensorPollingStrategy.h"
 #include "modules/sensor/SensorProviderProxy.h"
 #include "modules/sensor/SensorReading.h"
+#include "platform/UserGestureIndicator.h"
 
 using namespace device::mojom::blink;
 
 namespace blink {
 
+using mojom::blink::PermissionStatus;
+
 Sensor::Sensor(ScriptState* scriptState,
                const SensorOptions& sensorOptions,
                ExceptionState& exceptionState,
                SensorType type)
     : ActiveScriptWrappable(this),
       ContextLifecycleObserver(scriptState->getExecutionContext()),
       PageVisibilityObserver(
           toDocument(scriptState->getExecutionContext())->page()),
       m_sensorOptions(sensorOptions),
       m_type(type),
@@ skipping 34 matching lines @@
 
 void Sensor::start(ScriptState* scriptState, ExceptionState& exceptionState) {
   if (m_state != Sensor::SensorState::IDLE &&
       m_state != Sensor::SensorState::ERRORED) {
     exceptionState.throwDOMException(
         InvalidStateError,
         "Cannot start because SensorState is not idle or errored");
     return;
   }
 
+  // If the algorithm is not allowed to show a popup, throw SecurityError.
+  if (!UserGestureIndicator::consumeUserGesture()) {
+    exceptionState.throwDOMException(
+        SecurityError,
+        "Must be handling a user gesture to show a permission request.");
+    return;
+  }
+
   initSensorProxyIfNeeded();
-
   if (!m_sensorProxy) {
     exceptionState.throwDOMException(
         InvalidStateError, "The Sensor is no longer associated to a frame.");
     return;
   }
 
-  startListening();
+  m_sensorProxy->addObserver(this);
+  if (!m_sensorProxy->isInitialized()) {
+    m_sensorProxy->initialize();
+    return;
+  }
+
+  // Check the permission status.
+  auto permissionStatus = m_sensorProxy->getPermissionStatus();
+
+  if (permissionStatus == PermissionStatus::ASK) {
+    m_sensorProxy->setStartPendingPermission(true);
+    m_sensorProxy->requestPermission(scriptState->getExecutionContext(),
+                                     permissionStatus);
+    return;
+  }
+  if (permissionStatus == PermissionStatus::GRANTED) {
+    startListening();
+  } else if (permissionStatus == PermissionStatus::DENIED) {
+    stopListening();

[Mikhail, 2016/11/10 09:30:48]

how can be sensor listening in 'idle' or 'errored' state?

[riju_, 2016/11/14 14:00:06]

Done.

+
+    ConsoleMessage* consoleMessage = ConsoleMessage::create(
+        JSMessageSource, InfoMessageLevel, "Permission Denied.");
+    scriptState->getExecutionContext()->addConsoleMessage(consoleMessage);
+
+    exceptionState.throwDOMException(NotAllowedError, "Permission Denied.");
+  }
 }
 
 void Sensor::stop(ScriptState*, ExceptionState& exceptionState) {
   if (m_state == Sensor::SensorState::IDLE ||
       m_state == Sensor::SensorState::ERRORED) {
     exceptionState.throwDOMException(
         InvalidStateError,
         "Cannot stop because SensorState is either idle or errored");
     return;
   }
@@ skipping 49 matching lines @@
     return;
 
   Document* document = toDocument(getExecutionContext());
   if (!document || !document->frame())
     return;
 
   auto provider = SensorProviderProxy::from(document->frame());
   m_sensorProxy = provider->getSensor(m_type);
 
   if (!m_sensorProxy) {
-    m_sensorProxy =
-        provider->createSensor(m_type, createSensorReadingFactory());
+    m_sensorProxy = provider->createSensor(m_type, getExecutionContext(),
+                                           createSensorReadingFactory());
   }
 }
 
 void Sensor::contextDestroyed() {
   if (m_state == Sensor::SensorState::ACTIVE ||
       m_state == Sensor::SensorState::ACTIVATING)
     stopListening();
+  m_sensorProxy->resetPermissionService();

[Mikhail, 2016/11/10 09:30:48]

should be handled by proxy itself

[riju_, 2016/11/14 14:00:06]

Done.

 }
 
 void Sensor::onSensorInitialized() {
   if (m_state != Sensor::SensorState::ACTIVATING)
     return;
 
   startListening();
 }
 
 void Sensor::onSensorReadingChanged() {
   if (m_polling)
     m_polling->onSensorReadingChanged();
 }
 
+void Sensor::onSensorPermissionChanged() {

[Mikhail, 2016/11/10 09:30:48]

all this logic should be inside proxy itself

[riju_, 2016/11/14 14:00:06]

Done.

+  // Check the permission status.
+  auto permissionStatus = m_sensorProxy->getPermissionStatus();
+
+  if (permissionStatus != PermissionStatus::GRANTED) {
+    stopListening();
+    reportError(NotAllowedError,
+                "start/stop() call has failed as permission was denied.");
+  } else {
+    if (m_sensorProxy->getStartPendingPermission()) {
+      startListening();
+      m_sensorProxy->setStartPendingPermission(false);
+    }
+  }
+}
+
 void Sensor::onSensorError(ExceptionCode code,
                            const String& sanitizedMessage,
                            const String& unsanitizedMessage) {
   reportError(code, sanitizedMessage, unsanitizedMessage);
 }
 
 void Sensor::onStartRequestCompleted(bool result) {
   if (m_state != Sensor::SensorState::ACTIVATING)
     return;
 
@@ skipping 35 matching lines @@
     m_sensorProxy->suspend();
   } else {
     m_sensorProxy->resume();
   }
 }
 
 void Sensor::startListening() {
   DCHECK(m_sensorProxy);
   updateState(Sensor::SensorState::ACTIVATING);
 
-  m_sensorProxy->addObserver(this);
-  if (!m_sensorProxy->isInitialized()) {
-    m_sensorProxy->initialize();
-    return;
-  }
-
   if (!m_configuration) {
     m_configuration =
         createSensorConfig(m_sensorOptions, *m_sensorProxy->defaultConfig());
     DCHECK(m_configuration);
   }
 
   auto startCallback =
       WTF::bind(&Sensor::onStartRequestCompleted, wrapWeakPersistent(this));
   m_sensorProxy->addConfiguration(m_configuration->Clone(),
                                   std::move(startCallback));
@@ skipping 83 matching lines @@
 void Sensor::notifyStateChanged() {
   dispatchEvent(Event::create(EventTypeNames::statechange));
 }
 
 void Sensor::notifyError(DOMException* error) {
   dispatchEvent(
       SensorErrorEvent::create(EventTypeNames::error, std::move(error)));
 }
 
 }  // namespace blink