Replace ParsedDeclaration::expand with non-generic method

[SimonSapin]

... to reduce its code size impact.

https://bugzilla.mozilla.org/show_bug.cgi?id=1351737

---

This change is 

[highfive]

Heads up! This PR modifies the following files:

• @bholley: components/style/keyframes.rs, components/style/properties/declaration_block.rs, components/style/properties/properties.mako.rs
• @KiChjang: components/script/dom/cssstyledeclaration.rs
• @fitzgen: components/script/dom/cssstyledeclaration.rs
• @emilio: ports/geckolib/glue.rs, components/style/keyframes.rs, components/style/properties/declaration_block.rs, components/style/properties/properties.mako.rs

[highfive]

Warning

• These commits modify style and script code, but no tests are modified. Please consider adding a test!

[SimonSapin]

r? @Manishearth

[emilio]

@bors-servo r+

[bors-servo]

📌 Commit af037ae has been approved by emilio

[emilio]

@bors-servo r-

[emilio]

r=me with those fixed

[emilio]

This can't short-circuit.

[Manishearth]

Do we short circuit things with side effects?

[Manishearth]

Huh, we do. Interesting.

[SimonSapin]

The || operator doesn’t know whether its operands have side effects.

[emilio]

Nor this.

[Manishearth]

@bors-servo r+

[bors-servo]

📌 Commit af037ae has been approved by Manishearth

[Manishearth]

er.

[Manishearth]

@bors-servo r-

[emilio]

@bors-servo r+

[bors-servo]

📌 Commit 4f2b9a3 has been approved by emilio

[bors-servo]

⌛ Testing commit 4f2b9a3 with merge f3a5ad2...

[bors-servo]

💔 Test failed - linux-rel-wpt

[SimonSapin]

  ▶ CRASH [expected TIMEOUT] /html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_nonescaping-1.html
  │ 
  │ VMware, Inc.
  │ Gallium 0.4 on softpipe
  │ 3.3 (Core Profile) Mesa 12.0.1
  │ ERROR:script::dom::bindings::error: Error at http://web-platform.test:8000/html/semantics/embedded-content/the-iframe-element/iframe_sandbox_popups_helper-1.html:3:1 opener is not defined
  │ called `Result::unwrap()` on an `Err` value: Error { repr: Custom(Custom { kind: UnexpectedEof, error: StringError("failed to fill whole buffer") }) } (thread RenderBackend, at /checkout/src/libcore/result.rs:859)
  │ stack backtrace:
  │    0:     0x7f7f04f0f5fd - backtrace::backtrace::trace::h43650c97fbd1994d
  │    1:     0x7f7f04f0fc02 - backtrace::capture::Backtrace::new::hb5a725a088a2a2fc
  │    2:     0x7f7f047f33d7 - servo::main::{{closure}}::h9d96b5c32a8afffa
  │    3:     0x7f7f0675a13d - std::panicking::rust_panic_with_hook
  │                         at /checkout/src/libstd/panicking.rs:550
  │    4:     0x7f7f06759fd4 - std::panicking::begin_panic<collections::string::String>
  │                         at /checkout/src/libstd/panicking.rs:511
  │    5:     0x7f7f06759f09 - std::panicking::begin_panic_fmt
  │                         at /checkout/src/libstd/panicking.rs:495
  │    6:     0x7f7f06759e97 - std::panicking::rust_begin_panic
  │                         at /checkout/src/libstd/panicking.rs:471
  │    7:     0x7f7f0678669d - core::panicking::panic_fmt
  │                         at /checkout/src/libcore/panicking.rs:69
  │    8:     0x7f7f04c21d39 - core::result::unwrap_failed::h6bfb389c41db9e3b
  │    9:     0x7f7f04c8ee5d - webrender::render_backend::RenderBackend::run::hfa58adaca88f10b0
  │   10:     0x7f7f04c01cff - std::panicking::try::do_call::h17ab1154c25f8791
  │   11:     0x7f7f0676100a - panic_unwind::__rust_maybe_catch_panic
  │                         at /checkout/src/libpanic_unwind/lib.rs:98
  │   12:     0x7f7f04c22ef4 - <F as alloc::boxed::FnBox<A>>::call_box::h87f7ba67e73da805
  │   13:     0x7f7f06758c44 - alloc::boxed::{{impl}}::call_once<(),()>
  │                         at /checkout/src/liballoc/boxed.rs:650
  │                          - std::sys_common::thread::start_thread
  │                         at /checkout/src/libstd/sys_common/thread.rs:21
  │                          - std::sys::imp::thread::{{impl}}::new::thread_start
  │                         at /checkout/src/libstd/sys/unix/thread.rs:84
  │   14:     0x7f7f026be183 - start_thread
  │   15:     0x7f7f021d5bec - clone
  │   16:                0x0 - <unknown>
  │ ERROR:servo: called `Result::unwrap()` on an `Err` value: Error { repr: Custom(Custom { kind: UnexpectedEof, error: StringError("failed to fill whole buffer") }) }
  └ Pipeline failed in hard-fail mode.  Crashing!

@bors-servo retry #14323

[bors-servo]

⚡ Previous build results for android, arm32, arm64, linux-dev, mac-dev-unit, mac-rel-css, windows-msvc-dev are reusable. Rebuilding only linux-rel-css, linux-rel-wpt, mac-rel-wpt1, mac-rel-wpt2...

[bors-servo]

☀️ Test successful - android, arm32, arm64, linux-dev, linux-rel-css, linux-rel-wpt, mac-dev-unit, mac-rel-css, mac-rel-wpt1, mac-rel-wpt2, windows-msvc-dev
Approved by: emilio
Pushing f3a5ad2 to master...