value() can't assert hasValue() because too many places have plausible reasons for calling it on a PropertyDescriptor they basically know nothing about. One such place is CompartmentChecker::check(Handle<JSPropertyDescriptor>). Another is DefinePropertyByDescriptor. Maybe this will change with time.
In some cases we do things like `desc.hasWritable() && desc.writable() != existing_desc.writable()`. It is OK to write it this way, even though we have not checked existing_desc.hasWritable(), because in these cases we already know existingDesc is a complete property descriptor.
This adds support for class="reftest-opaque-layer" and for
reftest-assigned-layer="some-layer-name" to the reftest harness.
From reftest/README.txt:
Opaque Layer Tests: class="reftest-opaque-layer"
================================================
If an element should be assigned to a PaintedLayer that's opaque, set the class
"reftest-opaque-layer" on it. This checks whether the layer is opaque during
the last paint of the test, and it works whether your test is an invalidation
test or not. In order to pass the test, the element has to have a primary
frame, and that frame's display items must all be assigned to a single painted
layer and no other layers, so it can't be used on elements that create stacking
contexts (active or inactive).
Layerization Tests: reftest-assigned-layer="layer-name"
=======================================================
If two elements should be assigned to the same PaintedLayer, choose any string
value as the layer name and set the attribute reftest-assigned-layer="yourname"
on both elements. Reftest will check whether all elements with the same
reftest-assigned-layer value share the same layer. It will also test whether
elements with different reftest-assigned-layer values are assigned to different
layers.
The same restrictions as with class="reftest-opaque-layer" apply: All elements
must have a primary frame, and that frame's display items must all be assigned
to the same PaintedLayer and no other layers. If these requirements are not
met, the test will fail.
This also requires changing XMLHttpRequest so that it doesn't crash if
memory-mapping would be applicable but the channel has no associated
nsIFile; a regression test for that case is added.
Bonus fix: nsJARChannel::AsyncOpen now checks whether the inner channel's
AsyncOpen failed.
This bug will make jar:http:// no longer eligible for the memory-mapping
optimization tested in these test cases, so this patch changes them
to use local files, which is the case that that optimization is meant
for. Specifically, it changes them to chrome tests and pre-resolves
the chrome: URL of the jar file so that nsJARChannel recognizes it as a
local file.
Note that the bug 945152 test jar file remains in the file list for
plain mochitests as well as being added to chrome.ini; there is a test
in another directory that uses it, and a later patch in this series will
add another.
Add an ObjectOpResult out-param for DefineProperty functions everywhere. We leave a few js::DefineProperty() convenience functions with no *result out-param. These have strict behavior: that is, they automatically check the result and throw if it is false. In bug 1125624 these strict signatures may end up being called DefinePropertyOrThrow, as that is what the spec calls it.
