CheckAccessControls: begin refactor to allow better understanding of @fileoverview visibility.
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=75826151
Move IE readyState definition from Element to subtypes.

Unlike all Elements, these subtypes actually have
a readyState property (in at least some version of IE).
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=75835627
[NEW TYPE INFERENCE] Don't crash using THIS inside a generic class
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=75838367
Remove IE Event properties that are exact duplicates of gecko ones
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=75838868
Simplify parsing of default values in array patterns.

Previously, the parser was incorrectly parsing some array patterns as array literals, and we were hackishly converting them to patterns in NewIRFactory. Now the Parser does it right, so we can remove the hack.
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=75839243
Replace readyState prop of Document with HTMLDocument in externs

This seems to be more accurate representation of IE behavior.
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=75840226
Transpile destructuring patterns in for/in and for/of loops.
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=75841094
Ignore null mappings beyond the last line.
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=75841199
Remove Tween externs.
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=75842699