Allow data URLs to trigger downloads, as they do in Firefox....

Allow data URLs to trigger downloads, as they do in Firefox.

Unfortunately, many of our tests rely on being able to use WebURLLoader to load
data: URLs when there is no ResourceLoaderBridge implementation.  In those tests,
we would crash if we try to use the ResourceLoaderBridge.  To workaround that,
and because it probably a good optimization anyways, I decided to check if the
data URL has a supported MIME type, and if it does, then I let it load directly
as before.

Since data URLs may be very large, I modified DataURL::Parse to skip parsing the
'data' section of the URL if the corresponding out param is null.

R=tony
BUG=38546
TEST=none (I would like to add a download test, but they are all disabled or flaky.)


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=68212

[tony, 2010-12-02 01:07:40]

I see, LGTM.

[darin (slow to review), 2010-12-03 17:39:48]

Tony, please take another look.  I had to make some more changes to support our
tests.

I thought about adding a fast path for extracting the mime type from a data URL,
but I decided the complexity wasn't worth the runtime performance benefits.

[darin (slow to review), 2010-12-03 17:40:50]

Patch set #2 has the faster implementation, but it has the drawback of making
DataURL::Parse not validate the 'data' section of the URL.  That just didn't
seem worth it to me.

[tony, 2010-12-03 18:13:01]

On 2010/12/03 17:40:50, darin wrote:
> Patch set #2 has the faster implementation, but it has the drawback of making
> DataURL::Parse not validate the 'data' section of the URL.  That just didn't
> seem worth it to me.

LGTM, yeah, I agree that validating the data section doesn't seem important.