[PATCH] Add fallback for font loading when eval disabled

In some cases, such as in use with a CSP header, constructing a function with a
string of javascript is not allowed. However, compiling the various commands
that need to be done on the canvas element is faster than interpreting them.
This patch changes the font renderer to instead emit commands that are compiled
by the font loader. If, during compilation, we receive an EvalError, we instead
interpret them.

src/display/api.js

@@ -177,6 +177,14 @@ PDFJS.openExternalLinksInNewWindow = (
   PDFJS.openExternalLinksInNewWindow === undefined ?
     false : PDFJS.openExternalLinksInNewWindow);
 
+/**
+  * Determines if we can eval strings as JS. Primarily used to improve
+  * performance for font rendering.
+  * @var {boolean}
+  */
+PDFJS.isEvalSupported = (PDFJS.isEvalSupported === undefined ?
+                         true : PDFJS.isEvalSupported);
+
 /**
  * Document initialization / loading parameters object.
  *