Revert "Revert of Use the GrCacheable ID to eliminate the need for notifications to GrGpuGL when textures and RTs are… (https://codereview.chromium.org/376703009/)"

This reverts commit 249171e7d29b5559f3eefe9dbd437030bfad3fda.

Uses 32 bit id instead of 64. Renamed instanceID to uniqueID to match existing code.

R=robertphillips@google.com

Author: bsalomon@google.com

Review URL: https://codereview.chromium.org/414493002
diff --git a/src/gpu/GrBitmapTextContext.cpp b/src/gpu/GrBitmapTextContext.cpp
index 25c13ec..3ca98e4 100755
--- a/src/gpu/GrBitmapTextContext.cpp
+++ b/src/gpu/GrBitmapTextContext.cpp
@@ -56,7 +56,7 @@
 
     fCurrTexture = NULL;
     fCurrVertex = 0;
-    fEffectTextureGenID = 0;
+    fEffectTextureUniqueID = SK_InvalidUniqueID;
 
     fVertices = NULL;
     fMaxVertices = 0;
@@ -94,11 +94,11 @@
         SkASSERT(fCurrTexture);
         GrTextureParams params(SkShader::kRepeat_TileMode, GrTextureParams::kNone_FilterMode);
 
-        uint32_t textureGenID = fCurrTexture->getGenerationID();
+        uint32_t textureUniqueID = fCurrTexture->getUniqueID();
         
-        if (textureGenID != fEffectTextureGenID) {
+        if (textureUniqueID != fEffectTextureUniqueID) {
             fCachedEffect.reset(GrCustomCoordsTextureEffect::Create(fCurrTexture, params));
-            fEffectTextureGenID = textureGenID;
+            fEffectTextureUniqueID = textureUniqueID;
         }
 
         // This effect could be stored with one of the cache objects (atlas?)