Fixed more fuzzer issues

src/core/SkImageInfo.cpp

Index: src/core/SkImageInfo.cpp
diff --git a/src/core/SkImageInfo.cpp b/src/core/SkImageInfo.cpp
index 461bdc030985fb632141a487b7d04b1fec8dba27..967b4f6f08cee6ccb91d4f6c6547d6871b205c04 100644
--- a/src/core/SkImageInfo.cpp
+++ b/src/core/SkImageInfo.cpp
@@ -8,6 +8,14 @@
 #include "SkImageInfo.h"
 #include "SkFlattenableBuffers.h"
 
+static bool alpha_type_is_valid(SkAlphaType alphaType) {

[reed1, 2013/12/16 21:53:13]

not sure this will always work. If you declare the type to be an enum, the
compiler may decide that it can trust you, and remove the <= last check.

I *think* the safe way is to read ints from the buffer, pass ints to the
validate helpers, and only cast them down to the enum value when writing to
this.

[sugoi, 2013/12/17 15:55:45]

I can do that, but the examples I used, from SkValidationUtils.h, all have this
pattern, so I'd have to change these too, right ?

+    return (alphaType >= 0) && (alphaType <= kLastEnum_SkAlphaType);
+}
+
+static bool color_type_is_valid(SkColorType colorType) {
+    return (colorType >= 0) && (colorType <= kLastEnum_SkColorType);
+}
+
 void SkImageInfo::unflatten(SkFlattenableReadBuffer& buffer) {
     fWidth = buffer.read32();
     fHeight = buffer.read32();
@@ -16,6 +24,8 @@ void SkImageInfo::unflatten(SkFlattenableReadBuffer& buffer) {
     SkASSERT(0 == (packed >> 16));
     fAlphaType = (SkAlphaType)((packed >> 8) & 0xFF);
     fColorType = (SkColorType)((packed >> 0) & 0xFF);
+    buffer.validate(alpha_type_is_valid(fAlphaType) &&
+                    color_type_is_valid(fColorType));
 }
 
 void SkImageInfo::flatten(SkFlattenableWriteBuffer& buffer) const {