Change GrTextContext fallbacks to be a linked list chain.

src/gpu/GrTextContext.cpp

Index: src/gpu/GrTextContext.cpp
diff --git a/src/gpu/GrTextContext.cpp b/src/gpu/GrTextContext.cpp
index d281173dca5d95d12a870e77784471b1220afb89..2d19c40ac0f5bf546a042851b14232a77ca298f7 100644
--- a/src/gpu/GrTextContext.cpp
+++ b/src/gpu/GrTextContext.cpp
@@ -13,9 +13,14 @@
 #include "GrFontScaler.h"
 
 GrTextContext::GrTextContext(GrContext* context, const SkDeviceProperties& properties) :
+                            fFallbackTextContext(NULL),
                             fContext(context), fDeviceProperties(properties), fDrawTarget(NULL) {
 }
 
+GrTextContext::~GrTextContext() {
+    SkDELETE(fFallbackTextContext);

[bsalomon, 2014/10/13 18:46:36]

Feels like GrTC should be ref counted.

[jvanverth1, 2014/10/13 18:54:48]

I suppose, but while it's created by GrContext, it's only ever used by the
parent. I could create the fallback in the constructors for
GrDistanceFieldTextContext and GrStencilAndCoverTextContext, but I wasn't sure
if that's considered good practice.

[bsalomon, 2014/10/13 19:01:44]

I'd say either ref count or do as you suggested. Having a setter that takes
ownership from the caller feels unnecessarily dangerous unless it is really
evident from the name or very well documented.

[jvanverth1, 2014/10/13 19:06:18]

I'll add a factory function for each text context -- I think that'll take care
of any concerns.

+}
+
 void GrTextContext::init(const GrPaint& grPaint, const SkPaint& skPaint) {
     const GrClipData* clipData = fContext->getClip();