Refactor DrawingRecorders to check for cached drawings earlier

Source/web/WebFontImpl.cpp

Index: Source/web/WebFontImpl.cpp
diff --git a/Source/web/WebFontImpl.cpp b/Source/web/WebFontImpl.cpp
index 6411355fe47dc1591c2a559bf9a12d0d873ccac9..662930ecdbcf34c97166d3752a4f43f920415fcf 100644
--- a/Source/web/WebFontImpl.cpp
+++ b/Source/web/WebFontImpl.cpp
@@ -99,9 +99,8 @@ void WebFontImpl::drawText(WebCanvas* canvas, const WebTextRun& run, const WebFl
     SkPictureBuilder pictureBuilder(intRect);
     GraphicsContext* context = &pictureBuilder.context();
 
-    {
+    if (!DrawingRecorder::useCachedDrawingIfPossible(*context, *this, DisplayItem::WebFont)) {

[Xianzhu, 2015/07/03 01:24:42]

Nit: Another similar place still uses ASSERT. Better to keep consistence.

[pdr., 2015/07/03 02:38:05]

Good catch. Fixed.

         DrawingRecorder drawingRecorder(*context, *this, DisplayItem::WebFont, intRect);
-        ASSERT(!drawingRecorder.canUseCachedDrawing());
         context->save();
         context->setFillColor(color);
         context->clip(textClipRect);