If a user downgrades from Chromium 35+ to 34, then the PDF Viewer
extension will not work any more because the extension assumes
that certain features were available based on the cached feature
detection results.
To resolve this problem, all feature detection scripts run again
if the browser was downgraded.
In b5b94a4af3, i.e. PR #4259, we stopped using cidmaps.js. Despite that, it's still included when PDF.js is built. At almost 0.5 MB (and approx. 7000 lines), this is currently the single largest file in the codebase.
Including such a large file in the builds, when it is not actually used, seems extremely wasteful; hence this patch.
The absence of this property caused the following error in PDFView.download:
Cannot read property 'split' of undefined
This property was unset when the PDF was loaded through a typed array instead
of a URL. With the fix, the file name will default to "document.pdf", as
defined by getPDFFileNameFromURL in web/ui_utils.js
I have a large PDF where this function is called 1.6 million times
during loading. Minimizing the string concatenations reduces the
cumulative allocations done by Firefox within this function from 113 MB
to 48 MB.
The current way that the tabindices are defined, has the unfortunate consequence that adding a single button to the UI might mean having to change almost all tabindices. (This was the case in e.g. PR 4329.)
This patch attempts to avoid that situation happening again, by re-defining the tabindices slightly.
It's currently possible to step through the test results using the <kbd>N</kbd> and <kbd>P</kbd> keys, and you can also switch between test and reference images with the <kbd>T</kbd> key.
However if you want to highlight the differences, that can only be done by clicking. This has always annoyed me somewhat, so this patch adds support for toggling the differences view with the <kbd>D</kbd> key.
In the referenced issue, there is a PDF which uses a fill pattern which does not
have a matrix defined. This causes singularValueDecompose2dScale to fail with
undefined property error when accessing elements of that matrix.
This fix will only use the matrix when it is defined. The output for the PDF in
question now looks identical to chrome and preview with respect to the gradient
fill pattern.
