Use const where possible for drawing parameters

They should never be modified by a Renderer, only read and copied.

Change-Id: I9d8d55dca19115ee9dfeb2bb3f092ba2fb327cd4
diff --git a/libs/hwui/StatefulBaseRenderer.h b/libs/hwui/StatefulBaseRenderer.h
index 20eca22..bf34bec 100644
--- a/libs/hwui/StatefulBaseRenderer.h
+++ b/libs/hwui/StatefulBaseRenderer.h
@@ -69,9 +69,9 @@
     virtual void scale(float sx, float sy);
     virtual void skew(float sx, float sy);
 
-    virtual void setMatrix(SkMatrix* matrix);
+    virtual void setMatrix(const SkMatrix* matrix);
     void setMatrix(const Matrix4& matrix); // internal only convenience method
-    virtual void concatMatrix(SkMatrix* matrix);
+    virtual void concatMatrix(const SkMatrix* matrix);
     void concatMatrix(const Matrix4& matrix); // internal only convenience method
 
     // Clip
@@ -79,8 +79,8 @@
     virtual bool quickRejectConservative(float left, float top, float right, float bottom) const;
 
     virtual bool clipRect(float left, float top, float right, float bottom, SkRegion::Op op);
-    virtual bool clipPath(SkPath* path, SkRegion::Op op);
-    virtual bool clipRegion(SkRegion* region, SkRegion::Op op);
+    virtual bool clipPath(const SkPath* path, SkRegion::Op op);
+    virtual bool clipRegion(const SkRegion* region, SkRegion::Op op);
 
 protected:
     int getWidth() { return mWidth; }