Added the framework for having canvas/recorder/picture record depth_set's.

tests/CanvasTest.cpp

Index: tests/CanvasTest.cpp
diff --git a/tests/CanvasTest.cpp b/tests/CanvasTest.cpp
index 70c2c04ffabf511239239fe8fe3cf91ab78582af..c85fc1d4083e7af82034c9a8bead7070d22bf73e 100644
--- a/tests/CanvasTest.cpp
+++ b/tests/CanvasTest.cpp
@@ -779,6 +779,45 @@ DEF_TEST(Canvas_ClipEmptyPath, reporter) {
     canvas.restore();
 }
 
+#define SHADOW_TEST_CANVAS_CONST 10
+
+class SkShadowTestCanvas : public SkPaintFilterCanvas {
+public:
+
+    SkShadowTestCanvas(int x, int y, skiatest::Reporter* reporter)
+        : INHERITED(x,y)
+        , fReporter(reporter) {}
+
+    bool onFilter(SkTCopyOnFirstWrite<SkPaint>* paint, Type type) const {
+        REPORTER_ASSERT(this->fReporter, this->getZ() == SHADOW_TEST_CANVAS_CONST);
+
+        return true;
+    }
+
+    void testUpdateDepth(skiatest::Reporter *reporter) {
+        // set some depths (with picture enabled), then check them as they get set
+
+        REPORTER_ASSERT(reporter, this->getZ() == 0);
+        this->translateZ(-10);
+        REPORTER_ASSERT(reporter, this->getZ() == -10);
+
+        this->save();
+        this->translateZ(20);
+        REPORTER_ASSERT(reporter, this->getZ() == 10);
+
+        this->restore();
+        REPORTER_ASSERT(reporter, this->getZ() == -10);
+
+        this->translateZ(13.14f);
+        REPORTER_ASSERT(reporter, SkScalarNearlyEqual(this->getZ(), 3.14f));
+    }
+
+private:
+    skiatest::Reporter* fReporter;
+
+    typedef SkPaintFilterCanvas INHERITED;
+};
+
 namespace {
 
 class MockFilterCanvas : public SkPaintFilterCanvas {
@@ -812,4 +851,18 @@ DEF_TEST(PaintFilterCanvas_ConsistentState, reporter) {
     REPORTER_ASSERT(reporter, canvas.getTotalMatrix() == filterCanvas.getTotalMatrix());
     REPORTER_ASSERT(reporter, canvas.getClipBounds(&clip1) == filterCanvas.getClipBounds(&clip2));
     REPORTER_ASSERT(reporter, clip1 == clip2);
+
+    SkShadowTestCanvas* tCanvas = new SkShadowTestCanvas(100,100, reporter);
+    tCanvas->testUpdateDepth(reporter);
+    delete(tCanvas);
+
+    SkPictureRecorder recorder;
+    SkShadowTestCanvas *tSCanvas = new SkShadowTestCanvas(100, 100, reporter);
+    SkCanvas *tPCanvas = recorder.beginRecording(SkRect::MakeIWH(100, 100));
+
+    tPCanvas->translateZ(SHADOW_TEST_CANVAS_CONST);
+    sk_sp<SkPicture> pic = recorder.finishRecordingAsPicture();
+    tSCanvas->drawPicture(pic);
+
+    delete(tSCanvas);
 }