Remove incremental draw optimization from SkDebugCanvas

Remove incremental draw optimization from SkDebugCanvas

The SkDebugCanvas can be (or is currently) being used to draw to multiple
different canvases. If this use-case is intended, then storing draw
-related state in the canvas causes bugs.

Remove incremental draw from SkDebugCanvas. It can only optimize the
case where draw command index is advanced, no other changes are done
and no visualization is used. This case is not that critical, as it
happens only once per new frame at most. It causes bugs, because
one SkDebugCanvas is used to draw to multiple canvases.

Leave the draw to canvas in same state as it was passed in.

This fixes the debugger bugs where:
 * Old, stale image would stay on the raster canvas when a new image is
 loaded. Also happened with resizes.

 * Proper image for overdraw filter would be visible only for the first
   frame

Committed: https://skia.googlesource.com/skia/+/26a00de4f303fe74527f00b777a871843ae4437e

[Kimmo Kinnunen, 2015-01-07 12:08:39]

kkinnunen@nvidia.com changed reviewers:
+ robertphillips@google.com

[Kimmo Kinnunen, 2015-01-07 12:08:39]

This is the bug I set out to fix after the resize bug

[robertphillips, 2015-01-13 14:38:50]

lgtm. Note that the only-perform-the-next-draw optimization would/should've
fired all the time when stepping one command at a time through the picture. That
said it did introduce an inordinate amount of complexity and confusion to the
code.

[Kimmo Kinnunen, 2015-01-14 06:55:36]

The CQ bit was checked by kkinnunen@nvidia.com

[commit-bot: I haz the power, 2015-01-14 06:56:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/844493003/40001

[commit-bot: I haz the power, 2015-01-14 06:56:16]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-01-14 06:56:16]

Failed to apply patch for src/utils/debugger/SkDrawCommand.h:
While running git apply --index -3 -p1;
  error: patch failed: src/utils/debugger/SkDrawCommand.h:80
  Falling back to three-way merge...
  Applied patch to 'src/utils/debugger/SkDrawCommand.h' with conflicts.
  U src/utils/debugger/SkDrawCommand.h

Patch:       src/utils/debugger/SkDrawCommand.h
Index: src/utils/debugger/SkDrawCommand.h
diff --git a/src/utils/debugger/SkDrawCommand.h
b/src/utils/debugger/SkDrawCommand.h
index
831dffcfa04f8bc005b9439a52c65748223454bb..24c3bb30b8951efe54b31d5cebc637d3240f5e2a
100644
--- a/src/utils/debugger/SkDrawCommand.h
+++ b/src/utils/debugger/SkDrawCommand.h
@@ -42,10 +42,6 @@ public:
 
     virtual void setUserMatrix(const SkMatrix&) {}
 
-    /** Does nothing by default, but used by save() and restore()-type
-        subclasses to track unresolved save() calls. */
-    virtual void trackSaveState(int* state) {}
-
     // The next "active" system is only used by save, saveLayer, and restore.
     // It is used to determine which saveLayers are currently active (at a
     // given point in the rendering).
@@ -80,7 +76,6 @@ class SkRestoreCommand : public SkDrawCommand {
 public:
     SkRestoreCommand();
     virtual void execute(SkCanvas* canvas) const SK_OVERRIDE;
-    virtual void trackSaveState(int* state) SK_OVERRIDE;
     virtual Action action() const SK_OVERRIDE { return kPopLayer_Action; }
 
 private:
@@ -511,7 +506,6 @@ class SkSaveCommand : public SkDrawCommand {
 public:
     SkSaveCommand();
     virtual void execute(SkCanvas* canvas) const SK_OVERRIDE;
-    virtual void trackSaveState(int* state) SK_OVERRIDE;
     virtual Action action() const SK_OVERRIDE { return kPushLayer_Action; }
 private:
     typedef SkDrawCommand INHERITED;
@@ -523,7 +517,6 @@ public:
                        SkCanvas::SaveFlags flags);
     virtual void execute(SkCanvas* canvas) const SK_OVERRIDE;
     virtual void vizExecute(SkCanvas* canvas) const SK_OVERRIDE;
-    virtual void trackSaveState(int* state) SK_OVERRIDE;
     virtual Action action() const SK_OVERRIDE{ return kPushLayer_Action; }
     virtual void setActive(bool active) SK_OVERRIDE { fActive = active; }
     virtual bool active() const SK_OVERRIDE { return fActive; }

[Kimmo Kinnunen, 2015-01-14 06:58:47]

The CQ bit was checked by kkinnunen@nvidia.com

[commit-bot: I haz the power, 2015-01-14 06:59:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/844493003/60001

[commit-bot: I haz the power, 2015-01-14 07:09:22]

Committed patchset #4 (id:60001) as
https://skia.googlesource.com/skia/+/26a00de4f303fe74527f00b777a871843ae4437e