Fix check for valid proxies returned by AtlasManager.

Also renames a lot of variables to make it clearer that getProxies()
returns the number of instantiated proxies, not the number of all
proxies.

Bug: skia:
Change-Id: Ifbc910cbd6635dccdb4e7f0df2e69a0f341130af
Reviewed-on: https://skia-review.googlesource.com/128660
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Robert Phillips <robertphillips@google.com>
diff --git a/src/gpu/text/GrAtlasManager.h b/src/gpu/text/GrAtlasManager.h
index 9bf03c1..18ccfd0 100644
--- a/src/gpu/text/GrAtlasManager.h
+++ b/src/gpu/text/GrAtlasManager.h
@@ -30,13 +30,14 @@
 
     // if getProxies returns nullptr, the client must not try to use other functions on the
     // GrGlyphCache which use the atlas.  This function *must* be called first, before other
-    // functions which use the atlas.
-    const sk_sp<GrTextureProxy>* getProxies(GrMaskFormat format, unsigned int* numProxies) {
+    // functions which use the atlas. Note that we can have proxies available but none active
+    // (i.e., none instantiated).
+    const sk_sp<GrTextureProxy>* getProxies(GrMaskFormat format, unsigned int* numActiveProxies) {
         if (this->initAtlas(format)) {
-            *numProxies = this->getAtlas(format)->numActivePages();
+            *numActiveProxies = this->getAtlas(format)->numActivePages();
             return this->getAtlas(format)->getProxies();
         }
-        *numProxies = 0;
+        *numActiveProxies = 0;
         return nullptr;
     }