Stop overly conservative if-statement preservation.

Also remove deeply-checking isLowerPrecedenceInExpression, which is a case
that I don't think we ever need to check.
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=45935325
Make static methods static
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=45935883
Add buttons to mouse events.
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=45948020
Add a diagnostic group for "missing return"
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=46049553
Update type signature for profileEnd to match reality.
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=46053829
Add declarations for OfflineAudioContext and related classes.

Defines three classes:

OfflineAudioContext
OfflineAudioCompletionEvent
webkitOfflineAudioContext
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=46225016
Smarter minimization of conditional expressions.

Rather than the old heuristic which always tried to push
NOT nodes down toward the leaves of the AST, this new algorithm
constructs two ASTs for each condition (negated an unnegated)
and chooses between them depending on the context.
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=46230236
Remove unused error message: DETERMINISTIC_TEST_NO_RESULT
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=46245378