binding: Makes Dictionary handle a possible exception in [[Get]].

third_party/WebKit/Source/bindings/core/v8/DictionaryIterator.cpp

Index: third_party/WebKit/Source/bindings/core/v8/DictionaryIterator.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/DictionaryIterator.cpp b/third_party/WebKit/Source/bindings/core/v8/DictionaryIterator.cpp
index 444d225dcc84a911e16534a61787fd4dea01e32f..dc4c32d31a59b62a49a2e49b0856fe20097478bb 100644
--- a/third_party/WebKit/Source/bindings/core/v8/DictionaryIterator.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/DictionaryIterator.cpp
@@ -28,12 +28,17 @@ bool DictionaryIterator::next(ExecutionContext* executionContext,
                               ExceptionState& exceptionState) {
   DCHECK(!isNull());
 
+  v8::TryCatch tryCatch(m_isolate);
+
   v8::Local<v8::Value> next;
-  // TODO(alancutter): Support callable objects as well as functions.
   if (!v8Call(m_iterator->Get(m_isolate->GetCurrentContext(), m_nextKey),
               next) ||
       !next->IsFunction()) {
-    exceptionState.throwTypeError("Expected next() function on iterator.");
+    if (tryCatch.HasCaught()) {
+      exceptionState.rethrowV8Exception(tryCatch.Exception());
+    } else {
+      exceptionState.throwTypeError("Expected next() function on iterator.");
+    }
     m_done = true;
     return false;
   }
@@ -44,8 +49,12 @@ bool DictionaryIterator::next(ExecutionContext* executionContext,
                                            nullptr, m_isolate),
               result) ||
       !result->IsObject()) {
-    exceptionState.throwTypeError(
-        "Expected iterator.next() to return an Object.");
+    if (tryCatch.HasCaught()) {
+      exceptionState.rethrowV8Exception(tryCatch.Exception());
+    } else {
+      exceptionState.throwTypeError(
+          "Expected iterator.next() to return an Object.");
+    }
     m_done = true;
     return false;
   }
@@ -64,6 +73,9 @@ bool DictionaryIterator::next(ExecutionContext* executionContext,
   } else {
     m_done = false;
   }
+  if (tryCatch.HasCaught()) {
+    exceptionState.rethrowV8Exception(tryCatch.Exception());
+  }
   return !m_done;
 }