Rename toWebCoreString*() utility methods to toCoreString*()

Rename toWebCoreString*() utility methods to toCoreString*() as WebCore no
longer exists.

R=haraken, pfeldman
BUG=327338

Review URL: https://codereview.chromium.org/113213002

git-svn-id: svn://svn.chromium.org/blink/trunk@163759 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Refactor run-bindings-tests into 2 phases (generate + compare)

The new excess file check made the compare phase O(n^2) (i.e., slowed down
r-b-t), due to compare being done for the whole directory for each IDL file.

This fixes this bug, and simplifies the code, by splitting into 2 phases:
generate and compare.

This also makes it easier to debug the code generator, as r-b-t fails
immediately on crashes, rather than crashing repeatedly and then
complaining about diffs (due to missing files).

Followup to:
Add check to run-bindings-tests for excess files
https://codereview.chromium.org/112463002/

NOTRY=true

Review URL: https://codereview.chromium.org/113643002

git-svn-id: svn://svn.chromium.org/blink/trunk@163760 bbb929c8-8fbe-4397-9dbb-9b2b20218538