blink: permissions: add plumbing to revoke permissions

Source/modules/permissions/Permissions.cpp

Index: Source/modules/permissions/Permissions.cpp
diff --git a/Source/modules/permissions/Permissions.cpp b/Source/modules/permissions/Permissions.cpp
index 92e662af2b8ece2bfbb04555d3e97944c211b169..ad99d5919370ac6a17ec30974e13c1c53bb627b7 100644
--- a/Source/modules/permissions/Permissions.cpp
+++ b/Source/modules/permissions/Permissions.cpp
@@ -13,15 +13,58 @@
 #include "core/dom/DOMException.h"
 #include "core/dom/Document.h"
 #include "core/dom/ExceptionCode.h"
+#include "modules/permissions/PermissionCallback.h"
 #include "modules/permissions/PermissionController.h"
 #include "modules/permissions/PermissionDescriptor.h"
-#include "modules/permissions/PermissionQueryCallback.h"
 #include "modules/permissions/PermissionStatus.h"
 #include "public/platform/Platform.h"
 #include "public/platform/modules/permissions/WebPermissionClient.h"
 
 namespace blink {
 
+namespace {
+
+// Here we handle some common permission patterns to prevent propogation up to the content layer
+// Examples of behaviours which would go here are rejecting unsupported permissions, accepting
+// permissions which are always granted or always denied according to the spec etc.
+bool handleDefaultBehaviour(
+    ScriptState* scriptState, const ScriptValue& rawPermission, PassRefPtr<ScriptPromiseResolver> resolver, WebPermissionType type, TrackExceptionState& exceptionState)
+{
+    if (type == WebPermissionTypePushNotifications) {
+        PushPermissionDescriptor pushPermission = NativeValueTraits<PushPermissionDescriptor>::nativeValue(scriptState->isolate(), rawPermission.v8Value(), exceptionState);
+        // Only "userVisibleOnly" push is supported for now.
+        if (!pushPermission.userVisibleOnly()) {
+            resolver->reject(DOMException::create(NotSupportedError, "Push Permission without userVisibleOnly:true isn't supported yet."));
+            return true;
+        }
+    } else if (type == WebPermissionTypeMidiSysEx) {
+        MidiPermissionDescriptor midiPermission = NativeValueTraits<MidiPermissionDescriptor>::nativeValue(scriptState->isolate(), rawPermission.v8Value(), exceptionState);
+        // Only sysex usage requires a permission, otherwise it is granted.
+        if (!midiPermission.sysex()) {
+            resolver->resolve(PermissionStatus::create(scriptState->executionContext(), WebPermissionStatusGranted, WebPermissionTypeMidi));
+            return true;
+        }
+    }
+    return false;
+}
+
+WebPermissionType convertPermissionStringToType(const String& name)
+{
+    if (name == "geolocation")
+        return WebPermissionTypeGeolocation;
+    if (name == "notifications")
+        return WebPermissionTypeNotifications;
+    if (name == "push")
+        return WebPermissionTypePushNotifications;
+    if (name == "midi")
+        return WebPermissionTypeMidiSysEx;
+
+    ASSERT_NOT_REACHED();
+    return WebPermissionTypeGeolocation;
+}
+
+} // anonymous namespace
+
 // static
 WebPermissionClient* Permissions::getClient(ExecutionContext* executionContext)
 {
@@ -52,37 +95,41 @@ ScriptPromise Permissions::query(ScriptState* scriptState, const ScriptValue& ra
     ScriptPromise promise = resolver->promise();
 
     String name = permission.name();
-    WebPermissionType type;
-    if (name == "geolocation") {
-        type = WebPermissionTypeGeolocation;
-    } else if (name == "notifications") {
-        type = WebPermissionTypeNotifications;
-    } else if (name == "push") {
-        PushPermissionDescriptor pushPermission = NativeValueTraits<PushPermissionDescriptor>::nativeValue(scriptState->isolate(), rawPermission.v8Value(), exceptionState);
-        // Only "userVisibleOnly" push is supported for now.
-        if (!pushPermission.userVisibleOnly()) {
-            resolver->reject(DOMException::create(NotSupportedError, "Push Permission without userVisibleOnly:true isn't supported yet."));
-            return promise;
-        }
-        type = WebPermissionTypePushNotifications;
-    } else if (name == "midi") {
-        MidiPermissionDescriptor midiPermission = NativeValueTraits<MidiPermissionDescriptor>::nativeValue(scriptState->isolate(), rawPermission.v8Value(), exceptionState);
-        // Only sysex usage requires a permission, otherwise it is granted.
-        if (!midiPermission.sysex()) {
-            resolver->resolve(PermissionStatus::create(scriptState->executionContext(), WebPermissionStatusGranted, WebPermissionTypeMidi));
-            return promise;
-        }
-        type = WebPermissionTypeMidiSysEx;
-    } else {
-        ASSERT_NOT_REACHED();
-        type = WebPermissionTypeGeolocation;
-    }
+    WebPermissionType type = convertPermissionStringToType(name);
+
+    if (handleDefaultBehaviour(scriptState, rawPermission, resolver, type, exceptionState))
+        return promise;
 
     // If the current origin is a file scheme, it will unlikely return a
     // meaningful value because most APIs are broken on file scheme and no
     // permission prompt will be shown even if the returned permission will most
     // likely be "prompt".
-    client->queryPermission(type, KURL(KURL(), scriptState->executionContext()->securityOrigin()->toString()), new PermissionQueryCallback(resolver, type));
+    client->queryPermission(type, KURL(KURL(), scriptState->executionContext()->securityOrigin()->toString()), new PermissionCallback(resolver, type));
+    return promise;
+}
+
+ScriptPromise Permissions::revoke(ScriptState* scriptState, const ScriptValue& rawPermission)
+{
+    WebPermissionClient* client = getClient(scriptState->executionContext());
+    if (!client)
+        return ScriptPromise::rejectWithDOMException(scriptState, DOMException::create(InvalidStateError, "In its current state, the global scope can't revoke permissions."));
+
+    TrackExceptionState exceptionState;
+    PermissionDescriptor permission = NativeValueTraits<PermissionDescriptor>::nativeValue(scriptState->isolate(), rawPermission.v8Value(), exceptionState);
+
+    if (exceptionState.hadException())
+        return ScriptPromise::reject(scriptState, v8::Exception::TypeError(v8String(scriptState->isolate(), exceptionState.message())));
+
+    RefPtr<ScriptPromiseResolver> resolver = ScriptPromiseResolver::create(scriptState);
+    ScriptPromise promise = resolver->promise();
+
+    String name = permission.name();
+    WebPermissionType type = convertPermissionStringToType(name);
+
+    if (handleDefaultBehaviour(scriptState, rawPermission, resolver, type, exceptionState))
+        return promise;
+
+    client->revokePermission(type, KURL(KURL(), scriptState->executionContext()->securityOrigin()->toString()), new PermissionCallback(resolver, type));
     return promise;
 }