Implementing mixed content for forms posting to insecure location from secure ones

Source/core/frame/UseCounter.h

 /*
  * Copyright (C) 2012 Google, Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 416 matching lines @@
         CSSCharsetRuleEncoding = 426,
         DocumentSetCharset = 427,
         DocumentDefaultCharset = 428,
         TextEncoderConstructor = 429,
         TextEncoderEncode = 430,
         TextDecoderConstructor = 431,
         TextDecoderDecode= 432,
         FocusInOutEvent = 433,
         MouseEventMovementX = 434,
         MouseEventMovementY = 435,
+        MixedContentForm = 436,

[Mike West, 2014/06/06 12:18:18]

I should have been more clear: I think it would be valuable to split this
counter into three counters:

1. How many forms do we see, total?
2. How many mixed-content forms do we see?
3. How many mixed-content forms are submitted?

I'm not at all convinced that we'll be able to do anything with form submissions
without effecting some large subset of the web. I'm more optimistic about being
able to treat forms with insecure actions as passive mixed content. In order to
evaluate those, we'll need counters for both, and a baseline that tells us what
subset of the web we're effecting.

[mhm, 2014/06/06 19:11:59]

There is a counter already doing that (UseCounter::FormElement)
Now (UseCounter::MixedContentForm) is counting that.
Added (UseCounter::MixedContentSubmittedForm) for that.

         // Add new features immediately above this line. Don't change assigned
         // numbers of any item, and don't reuse removed slots.
         // Also, run update_use_counter_feature_enum.py in chromium/src/tools/metrics/histograms/
         // to update the UMA mapping.
         NumberOfFeatures, // This enum value must be last.
     };
 
     // "count" sets the bit for this feature to 1. Repeated calls are ignored.
     static void count(const Document&, Feature);
     // This doesn't count for non-Document ExecutionContext.
@@ skipping 45 matching lines @@
 
     void updateMeasurements();
 
     OwnPtr<BitVector> m_countBits;
     BitVector m_CSSFeatureBits;
 };
 
 } // namespace WebCore
 
 #endif // UseCounter_h