Initial HW layer support in new reorderer/renderer

Shares vast majority of clipped savelayer code, with only minor
differences in lifecycle.

Doesn't yet handle fill region, resize, or window transform.

Change-Id: Iabdd71811590d2b937eb11e1b01ce556ade54a5a
diff --git a/libs/hwui/BakedOpRenderer.h b/libs/hwui/BakedOpRenderer.h
index 16afad4..722bf02 100644
--- a/libs/hwui/BakedOpRenderer.h
+++ b/libs/hwui/BakedOpRenderer.h
@@ -37,7 +37,8 @@
 public:
     OffscreenBuffer(Caches& caches, uint32_t textureWidth, uint32_t textureHeight,
             uint32_t viewportWidth, uint32_t viewportHeight);
-
+    uint32_t viewportWidth;
+    uint32_t viewportHeight;
     Texture texture;
     Rect texCoords;
     Region region;
@@ -60,12 +61,16 @@
             , mOpaque(opaque) {
     }
 
+    static OffscreenBuffer* createOffscreenBuffer(uint32_t width, uint32_t height);
+    static void destroyOffscreenBuffer(OffscreenBuffer*);
+
     RenderState& renderState() { return mRenderState; }
     Caches& caches() { return mCaches; }
 
     void startFrame(uint32_t width, uint32_t height);
     void endFrame();
-    OffscreenBuffer* startLayer(uint32_t width, uint32_t height);
+    OffscreenBuffer* createLayer(uint32_t width, uint32_t height);
+    void startLayer(OffscreenBuffer* offscreenBuffer);
     void endLayer();
 
     Texture* getTexture(const SkBitmap* bitmap);