Switch HTMLCanvasElement over to new-style ExceptionState.

Set up the calling context on toDataURL()'s incoming ExceptionState
instead, for tidier generation of a possible SecurityError exception.

To support throwing context-sensitive SecurityErrors, extend
throwSecurityError() to also embellish its incoming messages.

R=
BUG=270033

Review URL: https://codereview.chromium.org/96203003

git-svn-id: svn://svn.chromium.org/blink/trunk@162887 bbb929c8-8fbe-4397-9dbb-9b2b20218538
12 files changed
tree: 95cf755d97aa4a0c86b326577f8608e6c4633117
  1. third_party/