Reland of permissions: remove duplicates from request multiple at the Blink level

third_party/WebKit/Source/modules/permissions/Permissions.cpp

Index: third_party/WebKit/Source/modules/permissions/Permissions.cpp
diff --git a/third_party/WebKit/Source/modules/permissions/Permissions.cpp b/third_party/WebKit/Source/modules/permissions/Permissions.cpp
index 1e6acc2955aa3b4d4b2b90709071b412f07f32df..c0d92a1cfc34953701f3791292e0bb6ff62a8140 100644
--- a/third_party/WebKit/Source/modules/permissions/Permissions.cpp
+++ b/third_party/WebKit/Source/modules/permissions/Permissions.cpp
@@ -23,6 +23,8 @@
 #include "platform/Logging.h"
 #include "public/platform/Platform.h"
 #include "public/platform/modules/permissions/WebPermissionClient.h"
+#include "wtf/NotFound.h"
+#include "wtf/Vector.h"
 
 namespace blink {
 
@@ -146,7 +148,8 @@
         return ScriptPromise::rejectWithDOMException(scriptState, DOMException::create(InvalidStateError, "In its current state, the global scope can't request permissions."));
 
     ExceptionState exceptionState(ExceptionState::GetterContext,  "request", "Permissions", scriptState->context()->Global(), scriptState->isolate());
-    OwnPtr<WebVector<WebPermissionType>> permissions = adoptPtr(new WebVector<WebPermissionType>(rawPermissions.size()));
+    OwnPtr<Vector<WebPermissionType>> internalPermissions = adoptPtr(new Vector<WebPermissionType>());
+    OwnPtr<Vector<int>> callerIndexToInternalIndex = adoptPtr(new Vector<int>(rawPermissions.size()));
     for (size_t i = 0; i < rawPermissions.size(); ++i) {
         const Dictionary& rawPermission = rawPermissions[i];
 
@@ -154,14 +157,25 @@
         if (exceptionState.hadException())
             return exceptionState.reject(scriptState);
 
-        permissions->operator[](i) = type.get();
-    }
-
-    ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
-    ScriptPromise promise = resolver->promise();
-
-    WebVector<WebPermissionType> permissionsCopy = *permissions;
-    client->requestPermissions(permissionsCopy, KURL(KURL(), scriptState->executionContext()->securityOrigin()->toString()), new PermissionsCallback(resolver, permissions.release()));
+        // Only append permissions to the vector that is passed to the client if it is not already
+        // in the vector (i.e. do not duplicate permisison types).
+        int internalIndex;
+        auto it = internalPermissions->find(type.get());
+        if (it == kNotFound) {
+            internalIndex = internalPermissions->size();
+            internalPermissions->append(type.get());
+        } else {
+            internalIndex = it;
+        }
+        callerIndexToInternalIndex->operator[](i) = internalIndex;
+    }
+
+    ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
+    ScriptPromise promise = resolver->promise();
+
+    WebVector<WebPermissionType> internalWebPermissions = *internalPermissions;
+    client->requestPermissions(internalWebPermissions, KURL(KURL(), scriptState->executionContext()->securityOrigin()->toString()),
+        new PermissionsCallback(resolver, internalPermissions.release(), callerIndexToInternalIndex.release()));
     return promise;
 }