Global FontPlatformData cache should use OwnPtr.
<http://webkit.org/b/111939>

Reviewed by Anders Carlsson.

Let the global FontPlatformData use OwnPtr instead of raw pointers + deleteAllValues().

* platform/graphics/FontCache.cpp:
(WebCore::FontCache::getCachedFontPlatformData):
(WebCore::FontCache::purgeInactiveFontData):
(WebCore::FontCache::invalidate):

    Tweaked code for OwnPtr. Also made getCachedFontPlatformData() do one hash lookup
    instead of two.

* platform/graphics/FontCache.h:
* platform/graphics/blackberry/FontCacheBlackBerry.cpp:
(WebCore::FontCache::createFontPlatformData):
* platform/graphics/chromium/FontCacheAndroid.cpp:
(WebCore::FontCache::createFontPlatformData):
* platform/graphics/freetype/FontCacheFreeType.cpp:
(WebCore::FontCache::createFontPlatformData):
* platform/graphics/mac/FontCacheMac.mm:
(WebCore::FontCache::createFontPlatformData):
* platform/graphics/qt/FontCacheQt.cpp:
(WebCore::FontCache::createFontPlatformData):
* platform/graphics/skia/FontCacheSkia.cpp:
(WebCore::FontCache::createFontPlatformData):
* platform/graphics/win/FontCacheWin.cpp:
(WebCore::FontCache::createFontPlatformData):
* platform/graphics/wince/FontCacheWinCE.cpp:
(WebCore::FontCache::createFontPlatformData):
* platform/graphics/wx/FontCacheWx.cpp:
(WebCore::FontCache::createFontPlatformData):

    FontCache::createFontPlatformData() now returns a PassOwnPtr.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@147639 268f45cc-cd09-0410-ab3c-d52691b4dbfc