surfaceflinger: Description init style change

We move the initialization of fields to Description's
declaration, and switch to using the "default" constructor and
destructor.

This is basically a style change, should essentially have no
difference in behavior, although it does subtly change
Description into being a POD (which might be useful for future
work, but should have no current impact).

Test: Built aosp_arm-eng
Change-Id: I79f91f422ff6ad55dbd9507ee6655f30377339a8
diff --git a/services/surfaceflinger/RenderEngine/Description.h b/services/surfaceflinger/RenderEngine/Description.h
index cbac855..1811952 100644
--- a/services/surfaceflinger/RenderEngine/Description.h
+++ b/services/surfaceflinger/RenderEngine/Description.h
@@ -36,27 +36,27 @@
     friend class ProgramCache;
 
     // whether textures are premultiplied
-    bool mPremultipliedAlpha;
+    bool mPremultipliedAlpha = false;
     // whether this layer is marked as opaque
-    bool mOpaque;
+    bool mOpaque = true;
 
     // Texture this layer uses
     Texture mTexture;
-    bool mTextureEnabled;
+    bool mTextureEnabled = false;
 
     // color used when texturing is disabled or when setting alpha.
     half4 mColor;
     // projection matrix
     mat4 mProjectionMatrix;
 
-    bool mColorMatrixEnabled;
+    bool mColorMatrixEnabled = false;
     mat4 mColorMatrix;
 
-    bool mIsWideGamut;
+    bool mIsWideGamut = false;
 
 public:
-    Description();
-    ~Description();
+    Description() = default;
+    ~Description() = default;
 
     void setPremultipliedAlpha(bool premultipliedAlpha);
     void setOpaque(bool opaque);