Fixed bug with SkImage leaving canvas backing store in an immutable state after destroy.

Added unit test that verifies that surface backing is writable after creating and destroying an image.
Review URL: https://codereview.chromium.org/13226002

git-svn-id: http://skia.googlecode.com/svn/trunk@8512 2bbb7eff-a529-9590-31e7-b0007b416f81

src/image/SkImage_Raster.cpp

@@ -100,7 +100,6 @@ SkImage_Raster::SkImage_Raster(const Info& info, SkPixelRef* pr, size_t rowBytes
     fBitmap.setConfig(config, info.fWidth, info.fHeight, rowBytes);
     fBitmap.setPixelRef(pr);
     fBitmap.setIsOpaque(isOpaque);
-    fBitmap.setImmutable();
 }
 
 SkImage_Raster::~SkImage_Raster() {}

tests/SurfaceTest.cpp

@@ -35,12 +35,8 @@ static SkSurface* createSurface(SurfaceType surfaceType, GrContext* context) {
     case kRaster_SurfaceType:
         return SkSurface::NewRaster(imageSpec);
     case kGpu_SurfaceType:
-#if SK_SUPPORT_GPU
         SkASSERT(NULL != context);
         return SkSurface::NewRenderTarget(context, imageSpec);
-#else
-        SkASSERT(0);
-#endif
     case kPicture_SurfaceType:
         return SkSurface::NewPicture(10, 10);
     }
@@ -133,18 +129,33 @@ static void TestSurfaceCopyOnWrite(skiatest::Reporter* reporter, SurfaceType sur
         testPaint))
 }
 
-static void TestSurface(skiatest::Reporter* reporter) {
-    TestSurfaceCopyOnWrite(reporter, kRaster_SurfaceType, NULL);
-    TestSurfaceCopyOnWrite(reporter, kPicture_SurfaceType, NULL);
+static void TestSurfaceWritableAfterSnapshotRelease(skiatest::Reporter* reporter,
+                                                    SurfaceType surfaceType,
+                                                    GrContext* context) {
+    // This test succeeds by not triggering an assertion.
+    // The test verifies that the surface remains writable (usable) after
+    // acquiring and releasing a snapshot without triggering a copy on write.
+    SkSurface* surface = createSurface(surfaceType, context);
+    SkAutoTUnref<SkSurface> aur_surface(surface);
+    SkCanvas* canvas = surface->getCanvas();
+    canvas->clear(1);
+    surface->newImageShapshot()->unref();  // Create and destroy SkImage
+    canvas->clear(2);
 }
 
-static void TestSurfaceGpu(skiatest::Reporter* reporter, GrContextFactory* factory) {
+static void TestSurface(skiatest::Reporter* reporter, GrContextFactory* factory) {
+    TestSurfaceCopyOnWrite(reporter, kRaster_SurfaceType, NULL);
+    TestSurfaceCopyOnWrite(reporter, kPicture_SurfaceType, NULL);
+    TestSurfaceWritableAfterSnapshotRelease(reporter, kRaster_SurfaceType, NULL);
+    TestSurfaceWritableAfterSnapshotRelease(reporter, kPicture_SurfaceType, NULL);
 #if SK_SUPPORT_GPU
-    GrContext* context = factory->get(GrContextFactory::kNative_GLContextType);
-    TestSurfaceCopyOnWrite(reporter, kGpu_SurfaceType, context);
+    if (NULL != factory) {
+        GrContext* context = factory->get(GrContextFactory::kNative_GLContextType);
+        TestSurfaceCopyOnWrite(reporter, kGpu_SurfaceType, context);
+        TestSurfaceWritableAfterSnapshotRelease(reporter, kGpu_SurfaceType, context);
+    }
 #endif
 }
 
 #include "TestClassDef.h"
-DEFINE_TESTCLASS("Surface", SurfaceTestClass, TestSurface)
-DEFINE_GPUTESTCLASS("SurfaceGpu", SurfaceGpuTestClass, TestSurfaceGpu)
+DEFINE_GPUTESTCLASS("Surface", SurfaceTestClass, TestSurface)