Bug 1313135 - Make an early return if the clip rect can be ignored. r=mchang

--HG--
extra : rebase_source : 3e1b5c15398a2536528c5b8799d2272ee4d07c66

gfx/skia/skia/src/gpu/GrClipStackClip.cpp

@@ -269,7 +269,8 @@ bool GrClipStackClip::apply(GrContext* context, GrDrawContext* drawContext, bool
     }
 
     SkRect devBounds = SkRect::MakeIWH(drawContext->width(), drawContext->height());
-    if (!devBounds.intersect(out->clippedDrawBounds())) {
+    if (!devBounds.intersect(out->clippedDrawBounds()) ||
+        GrClip::GetPixelIBounds(devBounds).isEmpty()) {
         return false;
     }
 

gfx/skia/skia/src/utils/SkLua.cpp

@@ -8,6 +8,7 @@
 #include "SkLua.h"
 
 #if SK_SUPPORT_GPU
+#include "GrClip.h"
 #include "GrReducedClip.h"
 #endif
 
@@ -642,6 +643,8 @@ int SkLua::lcanvas_getReducedClipStack(lua_State* L) {
 #if SK_SUPPORT_GPU
     const SkCanvas* canvas = get_ref<SkCanvas>(L, 1);
     SkRect queryBounds = SkRect::Make(canvas->getTopLayerBounds());
+    SkASSERT(!GrClip::GetPixelIBounds(queryBounds).isEmpty());
+
     const GrReducedClip reducedClip(*canvas->getClipStack(), queryBounds);
 
     GrReducedClip::ElementList::Iter iter(reducedClip.elements());