Culling API

*** SKP format breaking change ***

Adding a couple of culling primitives: pushCull(SkRect) & popCull().

These are currently only plumbed for SKP playback quickreject.

At record time, we perform a couple of optimizations to trim down the
number of redundant culls:

  * collapse empty pushCull/popCull pairs
  * skip pushCull/popCull pairs nested within an identical cull rect

Things still missing/to consider:

  * use an inlineable, simplified quickreject (Mike's old prototype)
  * debugger visualization for cull boxes
  * BBH integration: the initial prototype had some minimal BBH support,
    but since the optimizations required expensive rewinds and culling
    is expected to be a BBH alternative, it got dropped.

R=bsalomon@google.com, reed@google.com, robertphillips@google.com, caryclark@google.com, tomhudson@google.com, iancottrell@google.com

Author: fmalita@chromium.org

Review URL: https://codereview.chromium.org/138013009

git-svn-id: http://skia.googlecode.com/svn/trunk@13611 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/utils/SkDumpCanvas.cpp b/src/utils/SkDumpCanvas.cpp
index c8a94f4..d768137 100644
--- a/src/utils/SkDumpCanvas.cpp
+++ b/src/utils/SkDumpCanvas.cpp
@@ -297,6 +297,15 @@
     return this->INHERITED::clipRegion(deviceRgn, op);
 }
 
+void SkDumpCanvas::onPushCull(const SkRect& cullRect) {
+    SkString str;
+    toString(cullRect, &str);
+    this->dump(kCull_Verb, NULL, "pushCull(%s)", str.c_str());
+}
+
+void SkDumpCanvas::onPopCull() {
+    this->dump(kCull_Verb, NULL, "popCull()");
+}
 ///////////////////////////////////////////////////////////////////////////////
 
 void SkDumpCanvas::drawPaint(const SkPaint& paint) {