Building up "Fixes for SkRWBuffer"

tests/DataRefTest.cpp

Index: tests/DataRefTest.cpp
diff --git a/tests/DataRefTest.cpp b/tests/DataRefTest.cpp
index 002abcbe894a816301db7383c17adb79d10a9880..e60e56a70e91e480083fdd556f732a4022bcf951 100644
--- a/tests/DataRefTest.cpp
+++ b/tests/DataRefTest.cpp
@@ -245,7 +245,7 @@ static void check_abcs(skiatest::Reporter* reporter, const char buffer[], size_t
     }
 }
 
-// stream should contains an integral number of copies of gABC.
+// stream should contain an integral number of copies of gABC.
 static void check_alphabet_stream(skiatest::Reporter* reporter, SkStream* stream) {
     REPORTER_ASSERT(reporter, stream->hasLength());
     size_t size = stream->getLength();
@@ -284,29 +284,37 @@ static void check_alphabet_buffer(skiatest::Reporter* reporter, const SkROBuffer
     check_abcs(reporter, storage.get(), size);
 }
 
+#include "SkTaskGroup.h"
+
 DEF_TEST(RWBuffer, reporter) {
     // Knowing that the default capacity is 4096, choose N large enough so we force it to use
     // multiple buffers internally.
     const int N = 1000;
-    SkROBuffer* readers[N];
-    SkStream* streams[N];
 
     {
+        SkTaskGroup tasks;
         SkRWBuffer buffer;
         for (int i = 0; i < N; ++i) {
             buffer.append(gABC, 26);
-            readers[i] = buffer.newRBufferSnapshot();
-            streams[i] = buffer.newStreamSnapshot();
+            sk_sp<SkROBuffer> reader = sk_sp<SkROBuffer>(buffer.newRBufferSnapshot());
+            SkStream* stream = buffer.newStreamSnapshot();
+            REPORTER_ASSERT(reporter, reader->size() == buffer.size());
+            REPORTER_ASSERT(reporter, stream->getLength() == buffer.size());
+
+            // reader's copy constructor will ref the SkROBuffer, which will be unreffed
+            // when the task ends.
+            // Ownership of stream is passed to the task, which will delete it.
+            tasks.add([reporter, i, reader, stream] {
+                REPORTER_ASSERT(reporter, (i + 1) * 26U == reader->size());
+                REPORTER_ASSERT(reporter, stream->getLength() == reader->size());
+                check_alphabet_buffer(reporter, reader.get());
+                check_alphabet_stream(reporter, stream);
+                REPORTER_ASSERT(reporter, stream->rewind());
+                delete stream;
+            });
         }
         REPORTER_ASSERT(reporter, N*26 == buffer.size());
-    }
-
-    for (int i = 0; i < N; ++i) {
-        REPORTER_ASSERT(reporter, (i + 1) * 26U == readers[i]->size());
-        check_alphabet_buffer(reporter, readers[i]);
-        check_alphabet_stream(reporter, streams[i]);
-        readers[i]->unref();
-        delete streams[i];
+        tasks.wait();
     }
 }
 
@@ -325,9 +333,27 @@ DEF_TEST(RWBuffer_size, r) {
     REPORTER_ASSERT(r, 0 == iter.size());
 }
 
-// Tests that it is safe to destruct an SkRWBuffer without appending
-// anything to it.
+// Tests that operations (including the destructor) are safe on an SkRWBuffer
+// without any data appended.
 DEF_TEST(RWBuffer_noAppend, r) {
     SkRWBuffer buffer;
     REPORTER_ASSERT(r, 0 == buffer.size());
+
+    sk_sp<SkROBuffer> roBuffer = sk_sp<SkROBuffer>(buffer.newRBufferSnapshot());
+    REPORTER_ASSERT(r, roBuffer);
+    if (roBuffer) {
+        REPORTER_ASSERT(r, roBuffer->size() == 0);
+        SkROBuffer::Iter iter(roBuffer.get());
+        REPORTER_ASSERT(r, iter.size() == 0);
+        REPORTER_ASSERT(r, !iter.data());
+        REPORTER_ASSERT(r, !iter.next());
+    }
+
+    SkAutoTDelete<SkStream> stream(buffer.newStreamSnapshot());
+    REPORTER_ASSERT(r, stream);
+    if (stream) {
+        REPORTER_ASSERT(r, stream->hasLength());
+        REPORTER_ASSERT(r, stream->getLength() == 0);
+        REPORTER_ASSERT(r, stream->skip(10) == 0);
+    }
 }