Fix cases of variable shadowing in /samplecode/.

If we manage to fix all the existing cases of variable shadowing, we
could enable -Wshadow.

Change-Id: I4c476668a83a0054fe8624d5ffa650db202ba810
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/438376
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: Derek Sollenberger <djsollen@google.com>
Reviewed-by: Derek Sollenberger <djsollen@google.com>
diff --git a/samplecode/SampleClip.cpp b/samplecode/SampleClip.cpp
index 49da848..358e3f8 100644
--- a/samplecode/SampleClip.cpp
+++ b/samplecode/SampleClip.cpp
@@ -338,16 +338,16 @@
     draw_halfplane(canvas, pts[0], pts[1], c);
 }
 
-static void compute_half_planes(const SkMatrix& mx, SkScalar W, SkScalar H,
+static void compute_half_planes(const SkMatrix& mx, SkScalar width, SkScalar height,
                                 SkHalfPlane planes[4]) {
     SkScalar a = mx[0], b = mx[1], c = mx[2],
              d = mx[3], e = mx[4], f = mx[5],
              g = mx[6], h = mx[7], i = mx[8];
 
-    planes[0] = { 2*g - 2*a/W,  2*h - 2*b/W,  2*i - 2*c/W };
-    planes[1] = { 2*a/W,        2*b/W,        2*c/W };
-    planes[2] = { 2*g - 2*d/H,  2*h - 2*e/H,  2*i - 2*f/H };
-    planes[3] = { 2*d/H,        2*e/H,        2*f/H };
+    planes[0] = { 2*g - 2*a/width,  2*h - 2*b/width,  2*i - 2*c/width };
+    planes[1] = { 2*a/width,        2*b/width,        2*c/width };
+    planes[2] = { 2*g - 2*d/height, 2*h - 2*e/height, 2*i - 2*f/height };
+    planes[3] = { 2*d/height,       2*e/height,       2*f/height };
 }
 
 class HalfPlaneView2 : public Sample {
diff --git a/samplecode/SamplePolyToPoly.cpp b/samplecode/SamplePolyToPoly.cpp
index 04b2b71..41af4a0 100644
--- a/samplecode/SamplePolyToPoly.cpp
+++ b/samplecode/SamplePolyToPoly.cpp
@@ -50,21 +50,19 @@
 
             (void) m2.setPolyToPoly((const SkPoint*)src1, (SkPoint*)dst1, 4);
 
-            {
-                const SkPoint src[] = {
-                    { SkIntToScalar(1), SkIntToScalar(0) },
-                    { SkIntToScalar(4), SkIntToScalar(7) },
-                    { SkIntToScalar(10), SkIntToScalar(2) }
-                };
-                const SkPoint dst[] = {
-                    { SkIntToScalar(4), SkIntToScalar(2) },
-                    { SkIntToScalar(45), SkIntToScalar(26) },
-                    { SkIntToScalar(32), SkIntToScalar(17) }
-                };
+            const SkPoint src2[] = {
+                { SkIntToScalar(1), SkIntToScalar(0) },
+                { SkIntToScalar(4), SkIntToScalar(7) },
+                { SkIntToScalar(10), SkIntToScalar(2) }
+            };
+            const SkPoint dst2[] = {
+                { SkIntToScalar(4), SkIntToScalar(2) },
+                { SkIntToScalar(45), SkIntToScalar(26) },
+                { SkIntToScalar(32), SkIntToScalar(17) }
+            };
 
-                SkMatrix m0;
-                m0.setPolyToPoly(src, dst, 3);
-            }
+            SkMatrix m0;
+            m0.setPolyToPoly(src2, dst2, 3);
         }
     }
 
diff --git a/samplecode/SampleShadowUtils.cpp b/samplecode/SampleShadowUtils.cpp
index 15199e2..e313875 100644
--- a/samplecode/SampleShadowUtils.cpp
+++ b/samplecode/SampleShadowUtils.cpp
@@ -172,9 +172,9 @@
         SkTDArray<SkMatrix> matrices;
         matrices.push()->reset();
         matrices.push()->setRotate(33.f, 25.f, 25.f).postScale(1.2f, 0.8f, 25.f, 25.f);
-        SkPaint paint;
-        paint.setColor(SK_ColorGREEN);
-        paint.setAntiAlias(true);
+        SkPaint greenPaint;
+        greenPaint.setColor(SK_ColorGREEN);
+        greenPaint.setAntiAlias(true);
         SkPoint3 zPlaneParams = SkPoint3::Make(0, 0, std::max(1.0f, kHeight + fZDelta));
 
         // convex paths
@@ -195,7 +195,7 @@
 
                     canvas->save();
                     canvas->concat(m);
-                    this->drawShadowedPath(canvas, path, zPlaneParams, paint, kAmbientAlpha,
+                    this->drawShadowedPath(canvas, path, zPlaneParams, greenPaint, kAmbientAlpha,
                                            lightPos, kLightR, kSpotAlpha, flags);
                     canvas->restore();
 
@@ -221,8 +221,8 @@
 
                 canvas->save();
                 canvas->concat(m);
-                this->drawShadowedPath(canvas, path, zPlaneParams, paint, kAmbientAlpha, lightPos,
-                                       kLightR, kSpotAlpha, kNone_ShadowFlag);
+                this->drawShadowedPath(canvas, path, zPlaneParams, greenPaint, kAmbientAlpha,
+                                       lightPos, kLightR, kSpotAlpha, kNone_ShadowFlag);
                 canvas->restore();
 
                 canvas->translate(dx, 0);
@@ -236,10 +236,10 @@
         if (invCanvasM.invert(&invCanvasM)) {
             canvas->save();
             canvas->concat(invCanvasM);
-            SkPaint paint;
-            paint.setColor(SK_ColorBLACK);
-            paint.setAntiAlias(true);
-            canvas->drawCircle(lightPos.fX, lightPos.fY, kLightR / 10.f, paint);
+            SkPaint blackPaint;
+            blackPaint.setColor(SK_ColorBLACK);
+            blackPaint.setAntiAlias(true);
+            canvas->drawCircle(lightPos.fX, lightPos.fY, kLightR / 10.f, blackPaint);
             canvas->restore();
         }
     }
diff --git a/samplecode/SampleVariableWidthStroker.cpp b/samplecode/SampleVariableWidthStroker.cpp
index ab2117a..7d9a352 100644
--- a/samplecode/SampleVariableWidthStroker.cpp
+++ b/samplecode/SampleVariableWidthStroker.cpp
@@ -463,7 +463,7 @@
      * TODO: no reason this needs to return a vector of quads, can just append to the path
      */
     std::vector<PathSegment> strokeSegment(const PathSegment& seg,
-                                           const ScalarBezCurve& distFnc) const;
+                                           const ScalarBezCurve& distanceFunc) const;
 
     /** Adds an endcap to fOuter */
     enum class CapLocation { Start, End };
@@ -636,7 +636,7 @@
 }
 
 std::vector<SkVarWidthStroker::PathSegment> SkVarWidthStroker::strokeSegment(
-        const PathSegment& seg, const ScalarBezCurve& distFnc) const {
+        const PathSegment& seg, const ScalarBezCurve& distanceFunc) const {
     // Work item for the recursive splitting stack.
     struct Item {
         PathSegment fSeg;
@@ -659,7 +659,7 @@
 
     // Push the initial segment and distance function
     std::stack<Item> stack;
-    stack.push(Item(seg, distFnc, ScalarBezCurve::Mul(distFnc, distFnc)));
+    stack.push(Item(seg, distanceFunc, ScalarBezCurve::Mul(distanceFunc, distanceFunc)));
 
     std::vector<PathSegment> result;
     constexpr int kMaxIters = 5000; /** TODO: this is completely arbitrary */