Support RaisesException=Constructor and ConstructorCallWith with constructors with optional arguments.

Problem:
Previously, the variable declarations for ConstructorCallWith (document, executionContext) and  exception handling code are not generated (in cpp_method_call macro in method.cpp) for the case where some optional arguments are omitted.

Solution:
- Set the following flags in the constructor's context:
-- is_call_with_document and is_call_with_execution_context
-- is_raises_exception
- Generated the variable declarations in cpp_method_call
- Added test cases for ConstructorCallWith, RaisesException=Constructor and optional arguments in constructors in the Blink bindings tests.

This patch enables to fix Issue 378191:
- Modified WebSocket.idl using an optional parameter to make it closer to the spec.

BUG=378191

Review URL: https://codereview.chromium.org/352353002

git-svn-id: svn://svn.chromium.org/blink/trunk@177360 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Fix computation of the transformAncestor property in CompositingInputsUpdater.

The condition for being a transformAncestor should be transform(), not hasTransform().

BUG=390411

Review URL: https://codereview.chromium.org/368783002

git-svn-id: svn://svn.chromium.org/blink/trunk@177361 bbb929c8-8fbe-4397-9dbb-9b2b20218538