Implement SkAshmemDiscardableMemory

tests/DiscardableMemoryTest.cpp

Index: tests/DiscardableMemoryTest.cpp
diff --git a/tests/DiscardableMemoryTest.cpp b/tests/DiscardableMemoryTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..4f7a37f2e5be02df261c6ed2a7fe0e4f7fcb7aab
--- /dev/null
+++ b/tests/DiscardableMemoryTest.cpp
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkDiscardableMemory.h"
+
+#include "Test.h"
+#include "TestClassDef.h"
+
+DEF_TEST(DiscardableMemory, reporter) {
+    static const char testString[] = "HELLO, WORLD!";
+    SkDiscardableMemory* dm = SkDiscardableMemory::Create(sizeof(testString));
+    REPORTER_ASSERT(reporter, dm != NULL);
+    if (NULL == dm)

[scroggo, 2013/11/22 14:34:14]

Our style guide suggests using braces like so:

if (NULL == dm) {
    return;
}

[hal.canary, 2013/11/22 15:17:54]

Done.

+        return;
+    void* ptr = dm->data();
+    REPORTER_ASSERT(reporter, ptr != NULL);
+    memcpy(ptr, testString, sizeof(testString));
+    dm->unlock();
+    bool success = dm->lock();
+    REPORTER_ASSERT(reporter, success);
+    if (!success)

[scroggo, 2013/11/22 14:34:14]

braces

[hal.canary, 2013/11/22 15:17:54]

Done.

+        return;

[scroggo, 2013/11/22 14:34:14]

dm is leaked here. Maybe wrap it in an SkAutoTDelete?

[hal.canary, 2013/11/22 15:17:54]

Done.

+    ptr = dm->data();
+    REPORTER_ASSERT(reporter, 0 == memcmp(ptr, testString, sizeof(testString)));
+    dm->unlock();
+    SkDELETE(dm);
+}
+