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

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

Index: third_party/WebKit/Source/modules/sensor/SensorProxy.cpp
diff --git a/third_party/WebKit/Source/modules/sensor/SensorProxy.cpp b/third_party/WebKit/Source/modules/sensor/SensorProxy.cpp
index e3b01f30c0d560100a8eb40e5720b98fa23a2870..b67d4336a591e9fd198988095b98b2d8838d80c4 100644
--- a/third_party/WebKit/Source/modules/sensor/SensorProxy.cpp
+++ b/third_party/WebKit/Source/modules/sensor/SensorProxy.cpp
@@ -5,16 +5,26 @@
 #include "modules/sensor/SensorProxy.h"
 
 #include "core/frame/LocalFrame.h"
+#include "modules/permissions/PermissionUtils.h"
 #include "modules/sensor/SensorProviderProxy.h"
 #include "modules/sensor/SensorReading.h"
+#include "platform/UserGestureIndicator.h"
 #include "platform/mojo/MojoHelper.h"
+#include "platform/weborigin/SecurityOrigin.h"
 #include "public/platform/Platform.h"
+#include "wtf/RefPtr.h"
 
 using namespace device::mojom::blink;
 
 namespace blink {
 
+using mojom::blink::PermissionName;
+using mojom::blink::PermissionService;
+using mojom::blink::PermissionStatus;
+
 SensorProxy::SensorProxy(SensorType sensorType,
+                         PermissionService* permissionService,
+                         PassRefPtr<SecurityOrigin> origin,
                          SensorProviderProxy* provider,
                          std::unique_ptr<SensorReadingFactory> readingFactory)
     : m_type(sensorType),
@@ -24,7 +34,24 @@ SensorProxy::SensorProxy(SensorType sensorType,
       m_state(SensorProxy::Uninitialized),
       m_suspended(false),
       m_readingFactory(std::move(readingFactory)),
-      m_maximumFrequency(0.0) {}
+      m_maximumFrequency(0.0),
+      m_permissionStatus(PermissionStatus::ASK),
+      m_permissionService(permissionService),
+      m_securityOrigin(std::move(origin)) {}

[Mikhail, 2016/11/15 14:03:18]

no need to move PassRefPtr, I think PassRefPtr itself is deprecated now.

[riju_, 2016/11/16 12:38:25]

Done.

+
+void SensorProxy::onPermissionUpdate(PermissionStatus status) {
+  if (m_permissionStatus != status) {
+    m_permissionStatus = status;
+    SensorPermissionChanged();
+  }
+
+  // Keep listening to changes.
+  m_permissionService->GetNextPermissionChange(
+      createPermissionDescriptor(PermissionName::SENSORS), m_securityOrigin,
+      m_permissionStatus,
+      convertToBaseCallback(
+          WTF::bind(&SensorProxy::onPermissionUpdate, wrapPersistent(this))));
+}
 
 SensorProxy::~SensorProxy() {}
 
@@ -56,11 +83,14 @@ void SensorProxy::initialize() {
     return;
   }
 
-  m_state = Initializing;
-  auto callback = convertToBaseCallback(
-      WTF::bind(&SensorProxy::onSensorCreated, wrapWeakPersistent(this)));
-  m_provider->sensorProvider()->GetSensor(m_type, mojo::GetProxy(&m_sensor),
-                                          callback);
+  // Request permission.
+  if (m_permissionStatus == PermissionStatus::ASK) {

[Mikhail, 2016/11/15 14:03:18]

what if (m_permissionStatus != PermissionStatus::ASK) ? We should either
continue initialization or stop with error, depending on its actual value.

[riju_, 2016/11/16 12:38:25]

Done.

+    m_permissionService->RequestPermission(

[shalamov, 2016/11/14 14:40:06]

Can be garbage, if invalidated.

[riju_, 2016/11/16 12:38:25]

Acknowledged.

+        createPermissionDescriptor(PermissionName::SENSORS), m_securityOrigin,
+        UserGestureIndicator::processingUserGesture(),
+        convertToBaseCallback(
+            WTF::bind(&SensorProxy::onPermissionUpdate, wrapPersistent(this))));
+  }
 }
 
 void SensorProxy::addConfiguration(
@@ -128,6 +158,19 @@ void SensorProxy::SensorReadingChanged() {
     observer->onSensorReadingChanged();
 }
 
+void SensorProxy::SensorPermissionChanged() {
+  // If Permission is revoked throw error and reset connection.
+  if (m_permissionStatus != PermissionStatus::GRANTED) {
+    m_provider->onPermissionServiceConnectionError();

[shalamov, 2016/11/14 14:40:06]

This will invalidate permission proxy when permission is denied, consecutive
initialize will crash. If I read thru code correctly :D

[Mikhail, 2016/11/15 14:03:18]

we should prepare implementation for more granular permissions,
'handleSensorError' would be enough. Also 'onerror' event with an appropriate
description must be send to the user.

[riju_, 2016/11/16 12:38:25]

Acknowledged.

[riju_, 2016/11/16 12:38:25]

My bad, handleSensorError() is called now

+  } else {
+    m_state = Initializing;

[shalamov, 2016/11/14 14:40:07]

Can there be a case when we get "GRANTED" and proxy is already initialized?

[Mikhail, 2016/11/15 14:03:18]

we should not assign m_state here. What if SensorProxy is already initialized?

[riju_, 2016/11/16 12:38:26]

Added a check now, so that we don't call GetProxy more than once.

+    auto callback = convertToBaseCallback(
+        WTF::bind(&SensorProxy::onSensorCreated, wrapWeakPersistent(this)));
+    m_provider->sensorProvider()->GetSensor(m_type, mojo::GetProxy(&m_sensor),
+                                            callback);
+  }
+}
+
 void SensorProxy::handleSensorError(ExceptionCode code,
                                     String sanitizedMessage,
                                     String unsanitizedMessage) {