Revert of Improve usage of window rectangles

src/gpu/GrWindowRectangles.h

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrWindowRectangles_DEFINED
 #define GrWindowRectangles_DEFINED
 
 #include "GrNonAtomicRef.h"
 #include "SkRect.h"
 
 class GrWindowRectangles {
 public:
     constexpr static int kMaxWindows = 8;
 
-    GrWindowRectangles() : fCount(0) {}
+    enum class Mode : bool {
+        kExclusive,
+        kInclusive
+    };
+
+    GrWindowRectangles(Mode mode = Mode::kExclusive) : fMode(mode), fCount(0) {}
     GrWindowRectangles(const GrWindowRectangles& that) : fCount(0) { *this = that; }
     ~GrWindowRectangles() { SkSafeUnref(this->rec()); }
 
-    bool empty() const { return !fCount; }
+    Mode mode() const { return fMode; }
     int count() const { return fCount; }
+    bool disabled() const { return Mode::kExclusive == fMode && !fCount; }
     const SkIRect* data() const;
 
-    void reset();
+    void reset(Mode = Mode::kExclusive);
     GrWindowRectangles& operator=(const GrWindowRectangles&);
 
     SkIRect& addWindow(const SkIRect& window) { return this->addWindow() = window; }
     SkIRect& addWindow();
 
     bool operator!=(const GrWindowRectangles& that) const { return !(*this == that); }
     bool operator==(const GrWindowRectangles&) const;
 
 private:
     constexpr static int kNumLocalWindows = 1;
     struct Rec;
 
     const Rec* rec() const { return fCount <= kNumLocalWindows ? nullptr : fRec; }
 
-    int fCount;
+    Mode      fMode;
+    uint8_t   fCount;
     union {
         SkIRect   fLocalWindows[kNumLocalWindows]; // If fCount <= kNumLocalWindows.
         Rec*      fRec;                            // If fCount > kNumLocalWindows.
     };
 };
 
 struct GrWindowRectangles::Rec : public GrNonAtomicRef<Rec> {
     Rec(const SkIRect* windows, int numWindows) {
         SkASSERT(numWindows < kMaxWindows);
         memcpy(fData, windows, sizeof(SkIRect) * numWindows);
     }
 
     SkIRect fData[kMaxWindows];
 };
 
 inline const SkIRect* GrWindowRectangles::data() const {
     return fCount <= kNumLocalWindows ? fLocalWindows : fRec->fData;
 }
 
-inline void GrWindowRectangles::reset() {
+inline void GrWindowRectangles::reset(Mode mode) {
     SkSafeUnref(this->rec());
+    fMode = mode;
     fCount = 0;
 }
 
 inline GrWindowRectangles& GrWindowRectangles::operator=(const GrWindowRectangles& that) {
     SkSafeUnref(this->rec());
+    fMode = that.fMode;
     fCount = that.fCount;
     if (fCount <= kNumLocalWindows) {
         memcpy(fLocalWindows, that.fLocalWindows, fCount * sizeof(SkIRect));
     } else {
         fRec = SkRef(that.fRec);
     }
     return *this;
 }
 
 inline SkIRect& GrWindowRectangles::addWindow() {
     SkASSERT(fCount < kMaxWindows);
     if (fCount < kNumLocalWindows) {
         return fLocalWindows[fCount++];
     }
     if (fCount == kNumLocalWindows) {
         fRec = new Rec(fLocalWindows, kNumLocalWindows);
     } else if (!fRec->unique()) { // Simple copy-on-write.
         fRec->unref();
         fRec = new Rec(fRec->fData, fCount);
     }
     return fRec->fData[fCount++];
 }
 
 inline bool GrWindowRectangles::operator==(const GrWindowRectangles& that) const {
-    if (fCount != that.fCount) {
+    if (fMode != that.fMode || fCount != that.fCount) {
         return false;
     }
     if (fCount > kNumLocalWindows && fRec == that.fRec) {
         return true;
     }
     return !fCount || !memcmp(this->data(), that.data(), sizeof(SkIRect) * fCount);
 }
 
 #endif