Remove Unused method PlatformInstrumentation::willResizeImage and didResizeImage.
Remove Unused method PlatformInstrumentation::willResizeImage and didResizeImage.

As nothing calls this, removing it.

BUG=439559

Review URL: https://codereview.chromium.org/1153503008

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@196293 bbb929c8-8fbe-4397-9dbb-9b2b20218538

Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk,Pluto-tv/blink-crosswalk