Fix _check_upward_for_depot_tools in webkit_finder.py.

Simple fix in function that, as it seems, wasn't called a single time.

BUG=

Review URL: https://chromiumcodereview.appspot.com/24123004

git-svn-id: svn://svn.chromium.org/blink/trunk@157886 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Rename isolateFor*() utility functions to toIsolate()

Rename isolateFor*() utility functions to toIsolate() and leverage C++
overloading instead of having separate method names for each kind of
input.

R=abarth
BUG=263412

Review URL: https://chromiumcodereview.appspot.com/23477075

git-svn-id: svn://svn.chromium.org/blink/trunk@157887 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Reduce usage of v8::Isolate::GetCurrent() in NPV8Object

Reduce usage of v8::Isolate::GetCurrent() in NPV8Object and pass the isolate
around instead.

R=haraken
BUG=263412

Review URL: https://chromiumcodereview.appspot.com/23537048

git-svn-id: svn://svn.chromium.org/blink/trunk@157889 bbb929c8-8fbe-4397-9dbb-9b2b20218538