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

third_party/WebKit/Source/modules/sensor/Sensor.cpp

Index: third_party/WebKit/Source/modules/sensor/Sensor.cpp
diff --git a/third_party/WebKit/Source/modules/sensor/Sensor.cpp b/third_party/WebKit/Source/modules/sensor/Sensor.cpp
index c9f902d42ad470d7f9d58be39494524c9fa69d63..845587369ec27ee0952d5d02ec0b7aa69fee1fd1 100644
--- a/third_party/WebKit/Source/modules/sensor/Sensor.cpp
+++ b/third_party/WebKit/Source/modules/sensor/Sensor.cpp
@@ -13,11 +13,14 @@
 #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,
@@ -72,15 +75,47 @@ void Sensor::start(ScriptState* scriptState, ExceptionState& exceptionState) {
     return;
   }
 
-  initSensorProxyIfNeeded();
+  // 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) {
@@ -150,8 +185,8 @@ void Sensor::initSensorProxyIfNeeded() {
   m_sensorProxy = provider->getSensor(m_type);
 
   if (!m_sensorProxy) {
-    m_sensorProxy =
-        provider->createSensor(m_type, createSensorReadingFactory());
+    m_sensorProxy = provider->createSensor(m_type, getExecutionContext(),
+                                           createSensorReadingFactory());
   }
 }
 
@@ -159,6 +194,7 @@ 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() {
@@ -173,6 +209,22 @@ void Sensor::onSensorReadingChanged() {
     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) {
@@ -228,12 +280,6 @@ 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());