Let DM work without a GPU.

Testing:

/m/s/skia (dm) $ d dm; and env GYP_DEFINES=skia_gpu=0 d dm
ninja: Entering directory `out/Debug'
ninja: no work to do.
(294 GMs, 620 benches) x 4 configs, 245 tests
4507 tasks leftUnsupported vertex-color/texture xfer mode.
Unsupported vertex-color/texture xfer mode.
0 tasks left
416.53user 9.86system 0:47.43elapsed 898%CPU (0avgtext+0avgdata
13353376maxresident)k
0inputs+0outputs (0major+3579906minor)pagefaults 0swaps
ninja: Entering directory `out/Debug'
[909/909] LINK dm
(287 GMs, 612 benches) x 4 configs, 227 tests
0 tasks left
365.24user 7.71system 0:14.55elapsed 2562%CPU (0avgtext+0avgdata
14718912maxresident)k
0inputs+0outputs (0major+3328269minor)pagefaults 0swaps

BUG=skia:
R=bsalomon@google.com, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/213093004

git-svn-id: http://skia.googlecode.com/svn/trunk@13960 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/dm/DMTestTask.h b/dm/DMTestTask.h
index 87f5920..a65f096 100644
--- a/dm/DMTestTask.h
+++ b/dm/DMTestTask.h
@@ -48,7 +48,7 @@
     GpuTestTask(Reporter*, TaskRunner*, skiatest::TestRegistry::Factory);
 
     virtual void draw(GrContextFactory*) SK_OVERRIDE;
-    virtual bool shouldSkip() const SK_OVERRIDE { return false; }
+    virtual bool shouldSkip() const SK_OVERRIDE;
     virtual SkString name() const SK_OVERRIDE { return fName; }
 
 private: