Cleanup: Removing unnecessary args/complexity in SkSurface_Base and friends

src/image/SkSurface.cpp

Index: src/image/SkSurface.cpp
===================================================================
--- src/image/SkSurface.cpp	(revision 8683)
+++ src/image/SkSurface.cpp	(working copy)
@@ -59,28 +59,30 @@
     return fCachedImage;
 }
 
-void SkSurface_Base::aboutToDraw(SkCanvas* canvas) {
+void SkSurface_Base::aboutToDraw() {
     this->dirtyGenerationID();
 

[reed1, 2013/04/15 18:56:33]

How do we know that fCachedCanvas is always present?

[Justin Novosad, 2013/04/15 19:08:57]

Done.

-    if (canvas) {
-        SkASSERT(canvas == fCachedCanvas);
-        SkASSERT(canvas->getSurfaceBase() == this);
-        canvas->setSurfaceBase(NULL);
+    if (NULL == fCachedCanvas->getSurfaceBase()) {
+        // getSurfaceBase will be non-NULL if there are SkImages

[reed1, 2013/04/15 18:56:33]

Why is this test more robust than just checking fCachedImage for null?

[Justin Novosad, 2013/04/15 19:08:57]

Done.

+        // referencing the canvas backingstore
+        return;
     }
 
-    if (fCachedImage) {
-        // the surface may need to fork its backend, if its sharing it with
-        // the cached image. Note: we only call if there is an outstanding owner
-        // on the image (besides us).
-        if (fCachedImage->getRefCnt() > 1) {
-            this->onCopyOnWrite(fCachedImage, canvas);
-        }
+    SkASSERT(NULL != fCachedImage);
+    SkASSERT(fCachedCanvas->getSurfaceBase() == this);
+    fCachedCanvas->setSurfaceBase(NULL);
 
-        // regardless of copy-on-write, we must drop our cached image now, so
-        // that the next request will get our new contents.
-        fCachedImage->unref();
-        fCachedImage = NULL;
+    // the surface may need to fork its backend, if its sharing it with
+    // the cached image. Note: we only call if there is an outstanding owner
+    // on the image (besides us).
+    if (fCachedImage->getRefCnt() > 1) {
+        this->onCopyOnWrite();
     }
+
+    // regardless of copy-on-write, we must drop our cached image now, so
+    // that the next request will get our new contents.
+    fCachedImage->unref();
+    fCachedImage = NULL;
 }
 
 uint32_t SkSurface_Base::newGenerationID() {
@@ -110,7 +112,7 @@
 }
 
 void SkSurface::notifyContentChanged() {
-    asSB(this)->aboutToDraw(NULL);
+    asSB(this)->aboutToDraw();
 }
 
 SkCanvas* SkSurface::getCanvas() {