Introduce Caches::bindTexture() to reduce glBindTexture calls

Change-Id: Ic345422567c020c0a9035ff51dcf2ae2a1fc59f4
diff --git a/libs/hwui/TextDropShadowCache.h b/libs/hwui/TextDropShadowCache.h
index 0bed72b6..04d7357 100644
--- a/libs/hwui/TextDropShadowCache.h
+++ b/libs/hwui/TextDropShadowCache.h
@@ -30,6 +30,8 @@
 namespace android {
 namespace uirenderer {
 
+class Caches;
+
 struct ShadowText {
     ShadowText(): len(0), radius(0.0f), textSize(0.0f), typeface(NULL),
             flags(0), italicStyle(0.0f), scaleX(0), text(NULL), positions(NULL) {
@@ -114,7 +116,7 @@
  * Alpha texture used to represent a shadow.
  */
 struct ShadowTexture: public Texture {
-    ShadowTexture(): Texture() {
+    ShadowTexture(Caches& caches): Texture(caches) {
     }
 
     float left;