Free temporary GPU and memory resources held by inactive or hidden 2D canvases

Source/web/tests/Canvas2DLayerManagerTest.cpp

Index: Source/web/tests/Canvas2DLayerManagerTest.cpp
diff --git a/Source/web/tests/Canvas2DLayerManagerTest.cpp b/Source/web/tests/Canvas2DLayerManagerTest.cpp
index 8607ca5e2c55b6a223bb107214d48981b6853c9d..50400fc5c4778240b00c0972ad62106a2bc920e6 100644
--- a/Source/web/tests/Canvas2DLayerManagerTest.cpp
+++ b/Source/web/tests/Canvas2DLayerManagerTest.cpp
@@ -41,11 +41,22 @@ using testing::InSequence;
 using testing::Return;
 using testing::Test;
 
+namespace {
+
+class FakeCanvas2DLayerBridgeClient : public Canvas2DLayerBridgeClient {
+public:
+    FakeCanvas2DLayerBridgeClient() { m_hidden = false; }
+    virtual ~FakeCanvas2DLayerBridgeClient() { }
+    virtual bool hidden() const OVERRIDE { return m_hidden; }
+    void fakeHidden(bool value) { m_hidden = value; }
+private:
+    bool m_hidden;
+};
 
 class FakeCanvas2DLayerBridge : public Canvas2DLayerBridge {
 public:
     FakeCanvas2DLayerBridge(PassRefPtr<GraphicsContext3D> context, PassOwnPtr<SkDeferredCanvas> canvas)
-        : Canvas2DLayerBridge(context, canvas, 0, NonOpaque)
+        : Canvas2DLayerBridge(&m_client, context, canvas, 0, NonOpaque)
         , m_freeableBytes(0)
         , m_freeMemoryIfPossibleCount(0)
         , m_flushCount(0)
@@ -72,18 +83,19 @@ public:
         size_t bytesFreed = size < m_freeableBytes ? size : m_freeableBytes;
         m_freeableBytes -= bytesFreed;
         if (bytesFreed)
-            Canvas2DLayerManager::get().layerAllocatedStorageChanged(this, -((intptr_t)bytesFreed));
-        m_bytesAllocated -= bytesFreed;
+            storageAllocatedForRecordingChanged(m_bytesAllocated - bytesFreed);
         return bytesFreed;
     }
 
     virtual void flush() OVERRIDE
     {
         flushedDrawCommands();
+        m_freeableBytes = bytesAllocated();
         m_flushCount++;
     }
 
 public:
+    FakeCanvas2DLayerBridgeClient m_client;
     size_t m_freeableBytes;
     int m_freeMemoryIfPossibleCount;
     int m_flushCount;
@@ -111,6 +123,8 @@ static PassOwnPtr<SkDeferredCanvas> createCanvas(GraphicsContext3D* context)
     return adoptPtr(SkDeferredCanvas::Create(SkSurface::NewRasterPMColor(1, 1)));
 }
 
+} // unnamed namespace
+
 class Canvas2DLayerManagerTest : public Test {
 protected:
     void storageAllocationTrackingTest()
@@ -160,6 +174,40 @@ protected:
         EXPECT_EQ((size_t)5, layer->bytesAllocated());
     }
 
+    void hiddenCanvasTest()
+    {
+        RefPtr<GraphicsContext3D> context = GraphicsContext3D::createGraphicsContextFromWebContext(adoptPtr(new blink::MockWebGraphicsContext3D));
+        Canvas2DLayerManager& manager = Canvas2DLayerManager::get();
+        manager.init(20, 5);
+        OwnPtr<SkDeferredCanvas> canvas = createCanvas(context.get());
+        FakeCanvas2DLayerBridgePtr layer(adoptRef(new FakeCanvas2DLayerBridge(context, canvas.release())));
+        layer->fakeFreeableBytes(5);
+        layer->storageAllocatedForRecordingChanged(10);
+        manager.didHidePage(); // does nothing because no canvases are hidden
+        EXPECT_EQ(0, layer->m_freeMemoryIfPossibleCount);
+        EXPECT_EQ(0, layer->m_flushCount);
+        layer->m_client.fakeHidden(true);
+        manager.didHidePage();
+        EXPECT_EQ(1, layer->m_freeMemoryIfPossibleCount);
+        EXPECT_EQ((size_t)0, layer->m_freeableBytes);
+        EXPECT_EQ((size_t)0, layer->bytesAllocated());
+        EXPECT_EQ(1, layer->m_flushCount);
+    }
+
+    void addRemoveLayerTest()
+    {
+        RefPtr<GraphicsContext3D> context = GraphicsContext3D::createGraphicsContextFromWebContext(adoptPtr(new blink::MockWebGraphicsContext3D));
+        Canvas2DLayerManager& manager = Canvas2DLayerManager::get();
+        manager.init(10, 5);
+        OwnPtr<SkDeferredCanvas> canvas = createCanvas(context.get());
+        FakeCanvas2DLayerBridgePtr layer(adoptRef(new FakeCanvas2DLayerBridge(context, canvas.release())));
+        EXPECT_FALSE(manager.isInList(layer.get()));
+        layer->storageAllocatedForRecordingChanged(5);
+        EXPECT_TRUE(manager.isInList(layer.get()));
+        layer->storageAllocatedForRecordingChanged(0);
+        EXPECT_FALSE(manager.isInList(layer.get()));
+    }
+
     void flushEvictionTest()
     {
         RefPtr<GraphicsContext3D> context = GraphicsContext3D::createGraphicsContextFromWebContext(adoptPtr(new blink::MockWebGraphicsContext3D));
@@ -172,10 +220,10 @@ protected:
         EXPECT_EQ(0, layer->m_freeMemoryIfPossibleCount);
         layer->storageAllocatedForRecordingChanged(12); // over the max
         EXPECT_EQ(2, layer->m_freeMemoryIfPossibleCount); // Two tries, one before flush, one after flush
-        EXPECT_EQ((size_t)0, layer->m_freeableBytes);
+        EXPECT_EQ((size_t)5, layer->m_freeableBytes);
         EXPECT_EQ(1, layer->m_flushCount); // flush was attempted
-        EXPECT_EQ((size_t)11, layer->bytesAllocated()); // flush drops the layer from manager's tracking list
-        EXPECT_FALSE(manager.isInList(layer.get()));
+        EXPECT_EQ((size_t)5, layer->bytesAllocated());
+        EXPECT_TRUE(manager.isInList(layer.get()));
     }
 
     void doDeferredFrameTestTask(FakeCanvas2DLayerBridge* layer, bool skipCommands)
@@ -186,7 +234,6 @@ protected:
         EXPECT_TRUE(Canvas2DLayerManager::get().m_taskObserverActive);
         if (skipCommands) {
             layer->willUse();
-            layer->storageAllocatedForRecordingChanged(0);
             layer->skippedPendingDrawCommands();
         }
         blink::Platform::current()->currentThread()->exitRunLoop();
@@ -270,5 +317,15 @@ TEST_F(Canvas2DLayerManagerTest, testDeferredFrame)
     deferredFrameTest();
 }
 
-} // namespace
+TEST_F(Canvas2DLayerManagerTest, testHiddenCanvas)
+{
+    hiddenCanvasTest();
+}
+
+TEST_F(Canvas2DLayerManagerTest, testAddRemoveLayer)
+{
+    addRemoveLayerTest();
+}
+
+} // unnamed namespace