Add back destroyAll for Image::destroyDecodedData()

Image::destroyDecodedData(destroyAll = true) is called by MemoryCache
to prune image caches. In https://chromiumcodereview.appspot.com/15969015/
the parameter was removed, causing single-frame images to always keep
their decoded data. Caused bug 246830 because of the repeated calls to
Image::destroyDecodedData() from MemoryCache. It may also contribute to
bug 276666.

Add back the parameter.

BUG=276666,246830
R=pkasting
TBR=abarth (for core.gypi, ImageResource.cpp and other files changed because of now explicit parameter of BitmapImage::destroyDecodeData())
TEST=BitmapImageTest.destroyDecodedDataExceptCurrentFrame,BitmapImageTest.destroyAllDecodedData

Review URL: https://chromiumcodereview.appspot.com/22978024

git-svn-id: svn://svn.chromium.org/blink/trunk@156651 bbb929c8-8fbe-4397-9dbb-9b2b20218538