Adding more validation

- Added a way to check that the number of inputs of a filter is not more than a filter expects
- Added validation of reftype in SkBitmap::unflatten()
- Added validation on fKD (diffuse lighting constant) and fKS (specular lighting constant) to make sure that they are always non-negative numbers
- Added validation of SkPerlinNoiseShader::fType and SkPerlinNoiseShader::fNumOctaves

BUG=
R=reed@google.com, senorblanco@google.com, mtklein@google.com, senorblanco@chromium.org, sugoi@google.com

Author: sugoi@chromium.org

Review URL: https://codereview.chromium.org/83343003

git-svn-id: http://skia.googlecode.com/svn/trunk@12388 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/effects/SkTestImageFilters.cpp b/src/effects/SkTestImageFilters.cpp
index 2891131..cc6d1ad 100755
--- a/src/effects/SkTestImageFilters.cpp
+++ b/src/effects/SkTestImageFilters.cpp
@@ -76,7 +76,8 @@
     buffer.writeScalar(fScale);
 }
 
-SkDownSampleImageFilter::SkDownSampleImageFilter(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {
+SkDownSampleImageFilter::SkDownSampleImageFilter(SkFlattenableReadBuffer& buffer)
+  : INHERITED(1, buffer) {
     fScale = buffer.readScalar();
     buffer.validate(SkScalarIsFinite(fScale));
 }