Cleanup namespace usage in Source/web/Web*.h

This patch removes unnecessary blink:: prefixes.
Also it merges *namespace blink{}* blocks.
Also correcting blink presubmit errors in the changed files.

BUG=

Review URL: https://codereview.chromium.org/467573002

git-svn-id: svn://svn.chromium.org/blink/trunk@180126 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove some SVG equality operators

It seems these are not used (anymore).

Review URL: https://codereview.chromium.org/463173003

git-svn-id: svn://svn.chromium.org/blink/trunk@180127 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Delay posting "message" event on MediaKeySession if no event handlers.

A recent CL to Promises changed when JavaScript is run when a promise
is resolved. In the past the JS ran immediately -- now it is run
using a microtask. For EME code, the "message" event is generated right
after creating the session. It relies on the JS running and binding
an event handler. With the recent CL, it is possible for the event to
be generated before the handler is bound, so the event is lost. This
change delays posting the "message" event if there are no event handlers
registered.

BUG=402766,403121
TEST=Disabled EME browser_test passes

Review URL: https://codereview.chromium.org/465053002

git-svn-id: svn://svn.chromium.org/blink/trunk@180128 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Refactor module initialization.

Previous implementation had three CoreInitializer methods: initEventNames,
initEventTargetNames, and initBindings, which were never called, and
ModulesInitializer contained identically named methods which were a
superset of the base class implementation. This change removes duplication
and separates core and modules initialization for a cleaner implementation.

This change doesn't fix 393728, but is a necessary refactoring for the
actual fix.

BUG=393728

Review URL: https://codereview.chromium.org/464043002

git-svn-id: svn://svn.chromium.org/blink/trunk@180130 bbb929c8-8fbe-4397-9dbb-9b2b20218538