Store texture target on GrGLTexture. This is in preparation for using texture targets other than 2D.

src/gpu/gl/GrGLTexture.h

Index: src/gpu/gl/GrGLTexture.h
diff --git a/src/gpu/gl/GrGLTexture.h b/src/gpu/gl/GrGLTexture.h
index cffc64adc154153ae4063fcc1d520c4760e4bf20..40a68eb9e901e292d329745d504d612faf9cc468 100644
--- a/src/gpu/gl/GrGLTexture.h
+++ b/src/gpu/gl/GrGLTexture.h
@@ -28,6 +28,7 @@ public:
     };
 
     struct IDDesc {
+        GrGLenum                    fTarget;
         GrGLuint                    fTextureID;
         GrGpuResource::LifeCycle    fLifeCycle;
     };
@@ -52,6 +53,8 @@ public:
 
     GrGLuint textureID() const { return fTextureID; }
 
+    GrGLenum target() const { return fTarget; }
+
 protected:
     // The public constructor registers this object with the cache. However, only the most derived
     // class should register with the cache. This constructor does not do the registration and
@@ -69,6 +72,7 @@ protected:
 private:
     TexParams                       fTexParams;
     GrGpu::ResetTimestamp           fTexParamsTimestamp;
+    GrGLenum                        fTarget;
     GrGLuint                        fTextureID;
 
     // We track this separately from GrGpuResource because this may be both a texture and a render