IDL: Add toRestricted{Float,Double}() helpers to V8Binding.h

Source/bindings/core/v8/V8Binding.h

Index: Source/bindings/core/v8/V8Binding.h
diff --git a/Source/bindings/core/v8/V8Binding.h b/Source/bindings/core/v8/V8Binding.h
index f970537cedeea2703d77c79e186c9b8399261075..7becc4029284d98cddec34f5c0a3e4ddef99b875 100644
--- a/Source/bindings/core/v8/V8Binding.h
+++ b/Source/bindings/core/v8/V8Binding.h
@@ -468,6 +468,9 @@ uint64_t toUInt64(v8::Handle<v8::Value>);
 // Convert a value to a single precision float, which might fail.
 float toFloat(v8::Handle<v8::Value>, ExceptionState&);
 
+// Convert a value to a single precision float, throwing on non-finite values.
+float toRestrictedFloat(v8::Handle<v8::Value>, ExceptionState&);

[Jens Widell, 2015/01/21 13:35:10]

From a WebIDL POV, it could be argued to make more sense to have toFloat() and
toUnrestrictedFloat() here.

From a C++ POV, toFloat() and toRestrictedFloat() makes some sense, since the
C++ float type is unrestricted by default. And this is C++.

It doesn't look like toFloat()/toDouble() are used from non-generated code, so
changing their behavior should be non-intrusive. And, to make things clear, we
could of course have toRestrictedFloat() and toUnrestrictedFloat(), and no
toFloat() at all.

Opinions?

[bashi, 2015/01/22 02:11:14]

I don't have strong opinion here, but I prefer having toFloat() and
toRestrictedFloat() (i.e. this CL) because it wouldn't change the behavior of
toFloat() and I generally see this kind of mismatch from a C++ POV (not sure
it's a common among Blink developers, though). We might want to add a comment to
mention the mismatch.

[haraken, 2015/01/22 02:43:05]

+1 to toFloat() and toRestrictedFloat().

+
 // Convert a value to a single precision float assuming the conversion cannot fail.
 inline float toFloat(v8::Local<v8::Value> value)
 {
@@ -477,6 +480,9 @@ inline float toFloat(v8::Local<v8::Value> value)
 // Convert a value to a double precision float, which might fail.
 double toDouble(v8::Handle<v8::Value>, ExceptionState&);
 
+// Convert a value to a double precision float, throwing on non-finite values.
+double toRestrictedDouble(v8::Handle<v8::Value>, ExceptionState&);
+
 // Converts a value to a String, throwing if any code unit is outside 0-255.
 String toByteString(v8::Handle<v8::Value>, ExceptionState&);