Untriaging it so that it gets addressed.

This is an issue with an SVG rect width 100% not filling the SVG root completely as expected. I'll own it while I create a reduced case.

Minimal repro.

Deleted: zoomed-content-rounds-equally.html 386 bytes

zoomed-content-rounds-equally.html 386 bytes View Download

Wild guess: the CSS box painter int-snaps the background, but we naturally don't do that for SVG content.

(maybe the same root cause as issue 562973)

Right, the SVG box is being snapped when laid out into the page, but the rect is not. Not clear how fixable this is given SVG content does not, in theory, snap.

I guess there's nothing stopping snapping the viewport (SVGSVGElement::currentViewportSize), but that of course still leaves the viewBox transform et.c.

The annoying part is that the box painter snaps at paint time only, so there isn't a very good way to communicate that outside:

https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit/Source/core/paint/BoxPainter.cpp&l=324

On the plus side it looks like the SVG root painter also attempts to use pixel-snapped values: https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit/Source/core/paint/SVGRootPainter.cpp&l=73

What I think is missing is the residual scale adjustment: after snapping the size may be different and we need to adjust for that.

I'll take a stab.

https://codereview.chromium.org/1847983002/ should fix the SVG alignment issue.

However, for certain zoom levels and window sizes I'm still seeing white background bleed in the upper-right region (see attached).  That section is just an image, no SVG involved.

AFAICT this is a website styling bug:

  <div style="max-width: 1441px;">
    <div style="width: 100%; background-color: white;">
      ..
      <li style="width: 1440px;">
        <img style="width: 100%;">

The outer div width is pinned to 1441 while the image size is pinned to 1440.  Depending on zoom/offset, these can round differently resulting in the occasional 1px bg bleed (also visible in FF).

Deleted: bgbleed.png 301 KB

	bgbleed.png 301 KB View Download

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d1d05d02de7519c777358ce926c007a7222449d6

commit d1d05d02de7519c777358ce926c007a7222449d6
Author: fmalita <fmalita@chromium.org>
Date: Fri Apr 01 14:26:10 2016

[SVG] Compensate for container size snapping

BoxPainter rounds its box rect coordinates to ensure optimal alignment
and minimize AA bleed.

SVGRootPainter attempts to do the same, but it only adjusts the offset.

Since int-snapping may also change the size, the SVG content transform
needs to take this residual scale into account (such that it maps onto
the full int-snapped area).

BUG= 599095 
R=schenney@chromium.org,fs@opera.com,pdr@chromium.org

Review URL: https://codereview.chromium.org/1847983002

Cr-Commit-Position: refs/heads/master@{#384580}

[modify] https://crrev.com/d1d05d02de7519c777358ce926c007a7222449d6/third_party/WebKit/LayoutTests/TestExpectations
[add] https://crrev.com/d1d05d02de7519c777358ce926c007a7222449d6/third_party/WebKit/LayoutTests/svg/custom/zoomed-background-alignment-expected.html
[add] https://crrev.com/d1d05d02de7519c777358ce926c007a7222449d6/third_party/WebKit/LayoutTests/svg/custom/zoomed-background-alignment.html
[modify] https://crrev.com/d1d05d02de7519c777358ce926c007a7222449d6/third_party/WebKit/Source/core/paint/SVGRootPainter.cpp

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f025af09b2f7e8467df43ec231cfc986acb90111

commit f025af09b2f7e8467df43ec231cfc986acb90111
Author: Rebaseline Bot <blink-rebaseline-bot@chromium.org>
Date: Fri Apr 01 16:40:14 2016

Auto-rebaseline for r384580

https://chromium.googlesource.com/chromium/src/+/d1d05d02d

BUG= 599095 
TBR=fmalita@chromium.org

Review URL: https://codereview.chromium.org/1854793002 .

Cr-Commit-Position: refs/heads/master@{#384605}

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[modify] https://crrev.com/f025af09b2f7e8467df43ec231cfc986acb90111/third_party/WebKit/LayoutTests/platform/mac-mac10.10/fast/forms/calendar-picker/calendar-picker-appearance-zoom125-expected.png
[modify] https://crrev.com/f025af09b2f7e8467df43ec231cfc986acb90111/third_party/WebKit/LayoutTests/platform/mac-mac10.10/fast/images/color-profile-svg-fill-text-expected.png
[modify] https://crrev.com/f025af09b2f7e8467df43ec231cfc986acb90111/third_party/WebKit/LayoutTests/platform/mac-mac10.9/fast/forms/calendar-picker/calendar-picker-appearance-zoom125-expected.png
[modify] https://crrev.com/f025af09b2f7e8467df43ec231cfc986acb90111/third_party/WebKit/LayoutTests/platform/mac-mac10.9/fast/images/color-profile-svg-fill-text-expected.png
[modify] https://crrev.com/f025af09b2f7e8467df43ec231cfc986acb90111/third_party/WebKit/LayoutTests/platform/mac-mac10.9/svg/zoom/page/zoom-mask-with-percentages-expected.png
[modify] https://crrev.com/f025af09b2f7e8467df43ec231cfc986acb90111/third_party/WebKit/LayoutTests/platform/mac-mac10.9/svg/zoom/page/zoom-svg-float-border-padding-expected.png
[modify] https://crrev.com/f025af09b2f7e8467df43ec231cfc986acb90111/third_party/WebKit/LayoutTests/platform/mac/fast/forms/calendar-picker/calendar-picker-appearance-zoom125-expected.png
[modify] https://crrev.com/f025af09b2f7e8467df43ec231cfc986acb90111/third_party/WebKit/LayoutTests/platform/mac/fast/images/color-profile-svg-fill-text-expected.png
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[modify] https://crrev.com/f025af09b2f7e8467df43ec231cfc986acb90111/third_party/WebKit/LayoutTests/platform/win/fast/forms/calendar-picker/calendar-picker-appearance-zoom125-expected.png
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