unsigned -> int for counts and indices in picture-related code

also, (C)

BUG=skia:

Review URL: https://codereview.chromium.org/1300163002
diff --git a/src/core/SkRecorder.cpp b/src/core/SkRecorder.cpp
index c00a353..b12b1eb 100644
--- a/src/core/SkRecorder.cpp
+++ b/src/core/SkRecorder.cpp
@@ -245,7 +245,7 @@
 
 void SkRecorder::onDrawPosText(const void* text, size_t byteLength,
                                const SkPoint pos[], const SkPaint& paint) {
-    const unsigned points = paint.countText(text, byteLength);
+    const int points = paint.countText(text, byteLength);
     APPEND(DrawPosText,
            paint,
            this->copy((const char*)text, byteLength),
@@ -255,7 +255,7 @@
 
 void SkRecorder::onDrawPosTextH(const void* text, size_t byteLength,
                                 const SkScalar xpos[], SkScalar constY, const SkPaint& paint) {
-    const unsigned points = paint.countText(text, byteLength);
+    const int points = paint.countText(text, byteLength);
     APPEND(DrawPosTextH,
            paint,
            this->copy((const char*)text, byteLength),