[tor-bugs] #2872 [Tor Browser]: Limit the fonts available in TorBrowser

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#2872: Limit the fonts available in TorBrowser
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 Reporter:  mikeperry    |          Owner:  mikeperry
     Type:  enhancement  |         Status:  new      
 Priority:  normal       |      Milestone:           
Component:  Tor Browser  |        Version:           
 Keywords:               |         Parent:  #2871    
   Points:  16           |   Actualpoints:           
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Comment(by mikeperry):

 Beginning the descent down the rabbit hole on this.. Initial outlook is
 kind of bleak..

 The main font wrangling lives in gfx/thebes/gfxFont.h. There appears to be
 a mapping to attributes (perhaps for purposes of querying via javascript)
 in accessible/src/base/nsTextAttrs.h.

 Each OS seems to have its own set of classes in thebes for loading fonts.

 There appear to be a few rendering surfaces upon which gfxFonts can be
 used. These include:

 content/canvas/src/nsCanvasRenderingContext2D.cpp
 layout/generic/nsHTMLContainerFrame.cpp
 layout/svg/base/src/nsSVGGlyphFrame.h

 and a few others..

 CSS sheets appear to be represented via a linked list of nsStyleContexts.

 There is a possibility we could store the number of fonts loaded by CSS in
 either the parent nsIPresShell or the nsIDocShell, which I believe might
 be accessible for most of these surfaces.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/2872#comment:6>
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