Rationalize GrContext's Gr*Proxy getter naming

This CL replaces the entry points:

asDeferredSurface
asDeferredTexture
asDeferredRenderTarget

with:

GrSurfaceProxy* asSurfaceProxy
sk_sp<GrSurfaceProxy> asSurfaceProxyRef

GrTextureProxy* asTextureProxy
sk_sp<GrTextureProxy> asTextureProxyRef

GrRenderTargetProxy* asRenderTargetProxy
sk_sp<GrRenderTargetProxy> asRenderTargetProxyRef

Change-Id: I7c2b1ea3d702023ff23019815ca13c9ff6f3b32d
Reviewed-on: https://skia-review.googlesource.com/7741
Commit-Queue: Robert Phillips <robertphillips@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/text/GrAtlasGlyphCache.cpp b/src/gpu/text/GrAtlasGlyphCache.cpp
index 315b3c0..58e78c1 100644
--- a/src/gpu/text/GrAtlasGlyphCache.cpp
+++ b/src/gpu/text/GrAtlasGlyphCache.cpp
@@ -130,7 +130,7 @@
     sk_sp<GrSurfaceContext> sContext(context->contextPriv().makeWrappedSurfaceContext(
                                                                             sk_ref_sp(sProxy),
                                                                             nullptr));
-    if (!sContext || !sContext->asDeferredTexture()) {
+    if (!sContext || !sContext->asTextureProxy()) {
         return false;
     }