API functions returning Promises should not throw exceptions.

Source/bindings/core/v8/V8BindingMacros.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 52 matching lines @@
     type var;                                      \
     {                                              \
         v8::TryCatch block;                        \
         var = (value);                             \
         if (UNLIKELY(block.HasCaught())) {         \
             block.ReThrow();                       \
             return retVal;                         \
         }                                          \
     }
 
+// We need to cancel the exception propergation when we return a rejected
+// Promise.
+#define TONATIVE_VOID_PROMISE_INTERNAL(var, value, info)                                        \
+    var = (value);                                                                              \
+    if (UNLIKELY(block.HasCaught())) {                                                          \
+        v8SetReturnValue(info, ScriptPromise::rejectRaw(info.GetIsolate(), block.Exception())); \
+        block.Reset();                                                                          \
+        return;                                                                                 \
+    }
+
+#define TONATIVE_VOID_PROMISE(type, var, value, info)     \
+    type var;                                             \
+    {                                                     \
+        v8::TryCatch block;                               \
+        TONATIVE_VOID_PROMISE_INTERNAL(var, value, info); \
+    }
+
+
 #define TONATIVE_VOID_EXCEPTIONSTATE_INTERNAL(var, value, exceptionState) \
     var = (value);                                                        \
     if (UNLIKELY(block.HasCaught() || exceptionState.throwIfNeeded()))    \
         return;                                                           \
 
 #define TONATIVE_VOID_EXCEPTIONSTATE(type, var, value, exceptionState)     \
     type var;                                                              \
     {                                                                      \
         v8::TryCatch block;                                                \
         V8RethrowTryCatchScope rethrow(block);                             \
         TONATIVE_VOID_EXCEPTIONSTATE_INTERNAL(var, value, exceptionState); \
     }
 
 #define TONATIVE_DEFAULT_EXCEPTIONSTATE(type, var, value, exceptionState, retVal) \
     type var;                                                                     \
     {                                                                             \
         v8::TryCatch block;                                                       \
         V8RethrowTryCatchScope rethrow(block);                                    \
         var = (value);                                                            \
         if (UNLIKELY(block.HasCaught() || exceptionState.throwIfNeeded()))        \
             return retVal;                                                        \
     }
 
+// We need to cancel the exception propergation when we return a rejected
+// Promise.
+#define TONATIVE_VOID_EXCEPTIONSTATE_PROMISE_INTERNAL(var, value, exceptionState, info, scriptState) \
+    var = (value);                                                                                   \
+    if (UNLIKELY(block.HasCaught())) {                                                               \
+        v8SetReturnValue(info, ScriptPromise::rejectRaw(info.GetIsolate(), block.Exception()));      \
+        block.Reset();                                                                               \
+        return;                                                                                      \
+    }                                                                                                \
+    if (UNLIKELY(exceptionState.hadException())) {                                                   \
+        v8SetReturnValue(info, exceptionState.reject(scriptState).v8Value());                        \
+        return;                                                                                      \
+    }
+
+#define TONATIVE_VOID_EXCEPTIONSTATE_PROMISE(type, var, value, exceptionState, info, scriptState)     \
+    type var;                                                                                         \
+    {                                                                                                 \
+        v8::TryCatch block;                                                                           \
+        TONATIVE_VOID_EXCEPTIONSTATE_PROMISE_INTERNAL(var, value, exceptionState, info, scriptState); \
+    }
+
 // type is an instance of class template V8StringResource<>,
 // but Mode argument varies; using type (not Mode) for consistency
 // with other macros and ease of code generation
 #define TOSTRING_VOID(type, var, value) \
     type var(value);                    \
     if (UNLIKELY(!var.prepare()))       \
         return;
 
 #define TOSTRING_VOID_INTERNAL(var, value) \
     var = (value);                         \
     if (UNLIKELY(!var.prepare()))          \
         return;
 
 #define TOSTRING_DEFAULT(type, var, value, retVal) \
     type var(value);                               \
     if (UNLIKELY(!var.prepare()))                  \
         return retVal;
 
+// We need to cancel the exception propergation when we return a rejected
+// Promise.
+#define TOSTRING_VOID_PROMISE_INTERNAL(var, value, info)                                           \
+    var = (value);                                                                                 \
+    if (UNLIKELY(!var.prepare()))  {                                                               \
+        info.GetReturnValue().Set(ScriptPromise::rejectRaw(info.GetIsolate(), block.Exception())); \
+        block.Reset();                                                                             \
+        return;                                                                                    \
+    }
+
+#define TOSTRING_VOID_PROMISE(type, var, value, info)           \
+    type var;                                                   \
+    {                                                           \
+        v8::TryCatch block;                                     \
+        TOSTRING_VOID_PROMISE_INTERNAL(type, var, value, info); \
+    }
+
 } // namespace blink
 
 #endif // V8BindingMacros_h