Group the ImageDecoder::ZeroFill* functions together

This improve the placement and also permits us to cleanly revert
blink 153004

TBR=tkent@chromium.org
BUG=254462

Review URL: https://codereview.chromium.org/18146004

git-svn-id: svn://svn.chromium.org/blink/trunk@153322 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Insert sampling tracing macros to DOM methods

- Just in case, I didn't insert the macros to DOM methods that are marked
as [PerWorldBindings].

- Even if I inserted the macros to Document.getElementById() (which is marked
as [PerWorldBindings]), I couldn't observe performance regression in
PerformanceTests/Bindings/get-element-by-id.html.

BUG=241743
R=abarth

Review URL: https://chromiumcodereview.appspot.com/18118008

git-svn-id: svn://svn.chromium.org/blink/trunk@153323 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Revert "Speed up png decoding by eliminating branches from the core loop that fills ImageFrame with pixels"

The reverts commit c3e6f9a5eba02d448329456c66169b652086105b (r153004)
https://src.chromium.org/viewvc/blink?revision=153004&view=revision

Regressed image decode performance.
https://chromeperf.appspot.com/report?rev=209350&masters=ChromiumPerf&bots=chromium-rel-win7-gpu-intel&tests=image_decoding_measurement/ImageDecoding_avg

TBR=b.kelemen@sisa.samsung.com
BUG=254462

git-svn-id: svn://svn.chromium.org/blink/trunk@153324 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DateComponents shouldn't use bloatedCharacters

This code was already index-based, so converting it to use String instead of
UChar* was easy.

R=eseidel
BUG=254708

Review URL: https://chromiumcodereview.appspot.com/18318002

git-svn-id: svn://svn.chromium.org/blink/trunk@153325 bbb929c8-8fbe-4397-9dbb-9b2b20218538