Use SkError for a bitmap that could not be decoded.

tests/PictureTest.cpp

Index: tests/PictureTest.cpp
diff --git a/tests/PictureTest.cpp b/tests/PictureTest.cpp
index 6adfd5a9be1d19b1161cb24e05eb26045ad486ee..49ed7f3f0e5998cbe5e0b1e12a00d39ea0f36d4f 100644
--- a/tests/PictureTest.cpp
+++ b/tests/PictureTest.cpp
@@ -8,6 +8,7 @@
 #include "SkCanvas.h"
 #include "SkColorPriv.h"
 #include "SkData.h"
+#include "SkError.h"
 #include "SkPaint.h"
 #include "SkPicture.h"
 #include "SkRandom.h"
@@ -371,6 +372,10 @@ static SkData* serialized_picture_from_bitmap(const SkBitmap& bitmap) {
     return wStream.copyToData();
 }
 
+static void error_callback(SkError, void*) {
+    // Do nothing.
+}
+
 static void test_bitmap_with_encoded_data(skiatest::Reporter* reporter) {
     // Create a bitmap that will be encoded.
     SkBitmap original;
@@ -395,6 +400,16 @@ static void test_bitmap_with_encoded_data(skiatest::Reporter* reporter) {
     SkAutoDataUnref picture1(serialized_picture_from_bitmap(original));
     SkAutoDataUnref picture2(serialized_picture_from_bitmap(bm));
     REPORTER_ASSERT(reporter, picture1->equals(picture2));
+    // Now test that a parse error was generated when trying to create a new SkPicture without
+    // providing a function to decode the bitmap.
+    SkSetErrorCallback(error_callback, NULL);

[humper, 2013/04/25 17:07:08]

Is the idea here to silence the built-in default callback?  Maybe if all tests
are going to have to do that this should either get bumped up to the testing
infrastructure classes, or we should extend the error API to have a "shut up"
method?

+    SkMemoryStream pictureStream(picture1);
+    bool success;
+    SkClearLastError();
+    SkPicture pictureFromStream(&pictureStream, &success, NULL);
+    REPORTER_ASSERT(reporter, success);
+    REPORTER_ASSERT(reporter, SkGetLastError() == kParseError_SkError);
+    SkClearLastError();
 }
 
 static void test_clone_empty(skiatest::Reporter* reporter) {