[Sensors] Allow Sensor API only on secure top-level browsing contexts and add frequency checks

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 872afd786fdd7de5f4333a06813c33abd1eb43ad..716713c93032958ce442a110052e43f0a7b8632b 100644
--- a/third_party/WebKit/Source/modules/sensor/Sensor.cpp
+++ b/third_party/WebKit/Source/modules/sensor/Sensor.cpp
@@ -17,15 +17,40 @@ using namespace device::mojom::blink;
 
 namespace blink {
 
-Sensor::Sensor(ExecutionContext* executionContext, const SensorOptions& sensorOptions, SensorType type)
+Sensor::Sensor(ScriptState* scriptState, const SensorOptions& sensorOptions, ExceptionState& exceptionState, SensorType type)
     : ActiveScriptWrappable(this)
-    , ContextLifecycleObserver(executionContext)
-    , PageVisibilityObserver(toDocument(executionContext)->page())
+    , ContextLifecycleObserver(scriptState->getExecutionContext())
+    , PageVisibilityObserver(toDocument(scriptState->getExecutionContext())->page())
     , m_sensorOptions(sensorOptions)
     , m_type(type)
     , m_state(Sensor::SensorState::IDLE)
     , m_storedData()
 {
+    // Check secure context.
+    String errorMessage;
+    if (!scriptState->getExecutionContext()->isSecureContext(errorMessage)) {
+        exceptionState.throwDOMException(SecurityError, errorMessage);
+        return;
+    }
+
+    // Check top-level browsing context.
+    if (!scriptState->domWindow() || !scriptState->domWindow()->frame() || !scriptState->domWindow()->frame()->isMainFrame()) {
+        exceptionState.throwSecurityError("Must be in a top-level browsing context");
+        return;
+    }
+
+    // Check the given frequency value.
+    if (m_sensorOptions.hasFrequency()) {
+        double frequency = m_sensorOptions.frequency();
+        if (frequency <= 0.0) {
+            exceptionState.throwRangeError("Frequency must be positive.");
+            return;
+        }
+        // Cap to 60.0 Hz
+        const double kMaxAllowedFrequency = 60.0;

[timvolodine, 2016/09/19 16:52:13]

think this should be a more 'global' constant somewhere. perhaps a dedicated .h
file in modules/sensor or common..

[Mikhail, 2016/09/20 13:29:37]

Done.

+        if (frequency > kMaxAllowedFrequency)
+            m_sensorOptions.setFrequency(kMaxAllowedFrequency);
+    }

[timvolodine, 2016/09/19 16:52:13]

don't know what the spec says here, maybe output some message to console for
developers to know there is capping..

[Mikhail, 2016/09/20 13:29:37]

Done.

 }
 
 Sensor::~Sensor() = default;