Reland: Use FontFallbackPriority Fonts in FontFallbackIterator
Now that the pieces are in place, use the emoji and symbol fonts in
FontFallbackIterator. Previously FontCache's character fallback
functions were extended so that they take FontFallbackPriority into
account. These functions can now be used in FontFallbackIterator as a
fallback priority stage where those fonts are used as the first fallback
font in order to correctly distinguish between emoji and text
presentation emoji.
Relanded after revert in https://codereview.chromium.org/1758383002/
Rebaselining the test results since now the emoji font is used more
often.
Original issue LGTM'ed in https://codereview.chromium.org/1672553004/
BUG=549571,591778
TBR=eae, behdad
Review URL: https://codereview.chromium.org/1764933002
Cr-Commit-Position: refs/heads/master@{#379249}
7 files changed
