Fix double lock of texture resource in software renderer

cc/trees/layer_tree_host_pixeltest_readback.cc

Index: cc/trees/layer_tree_host_pixeltest_readback.cc
diff --git a/cc/trees/layer_tree_host_pixeltest_readback.cc b/cc/trees/layer_tree_host_pixeltest_readback.cc
index 0a06144e87c3481937292b558560558471f28e50..4a2855fec27a8fe6ca66431240fe83a63f65f364 100644
--- a/cc/trees/layer_tree_host_pixeltest_readback.cc
+++ b/cc/trees/layer_tree_host_pixeltest_readback.cc
@@ -1144,6 +1144,33 @@ TEST_F(LayerTreeHostReadbackPixelTest, ReadbackNonRootLayerOutsideViewport) {
       base::FilePath(FILE_PATH_LITERAL("green_with_blue_corner.png")));
 }
 
+class LayerTreeHostReadbackCrashPixelTest
+    : public LayerTreeHostReadbackPixelTest,
+      public testing::WithParamInterface<bool> {};
+
+TEST_P(LayerTreeHostReadbackCrashPixelTest,

[danakj, 2015/02/06 18:57:26]

LTHReadbackNonFirstNonRootRenderPassTest?

+       ReadbackNonRootOrFirstLayer) {
+  scoped_refptr<SolidColorLayer> background =

[danakj, 2015/02/06 18:57:26]

Can you add comment explaining this test has 3 render passes with the copy
request on the renderpass in the middle. Doing a copy request can be destructive
of state, so for renderpasses after the first drawn the code path is different.
This verifies the non-first and non-root path. And reference
http://crbug.com/99393.

+      CreateSolidColorLayer(gfx::Rect(200, 200), SK_ColorGREEN);
+  background->SetForceRenderSurface(true);
+
+  scoped_refptr<SolidColorLayer> blue =
+      CreateSolidColorLayer(gfx::Rect(150, 150, 50, 50), SK_ColorBLUE);
+  blue->SetForceRenderSurface(true);

[danakj, 2015/02/06 18:57:26]

can you also put a copy request on here (see line 630 for an example) so that
the other one is the 2nd copy request instead of just the 2nd renderpass? that
should make this test more futureproof.

+  background->AddChild(blue);
+
+  RunReadbackTestWithReadbackTarget(
+      GetParam() ? PIXEL_TEST_GL : PIXEL_TEST_SOFTWARE,
+      READBACK_DEFAULT,
+      background,
+      background.get(),
+      base::FilePath(FILE_PATH_LITERAL("green_with_blue_corner.png")));
+}
+
+INSTANTIATE_TEST_CASE_P(LayerTreeHostReadbackCrashPixelTests,
+                        LayerTreeHostReadbackCrashPixelTest,
+                        testing::Bool());
+
 }  // namespace
 }  // namespace cc