Fix up -Winconsistent-missing-override

  (and a couple presubmit fixes)

This allows us to turn back on -Werror for LLVM coverage builds,
and more generally supports building with Clang 3.7.

No public API changes.
TBR=reed@google.com

BUG=skia:

Review URL: https://codereview.chromium.org/1232463006

1 files changed, 3 insertions, 3 deletions

diff --git a/gm/bitmapshader.cpp b/gm/bitmapshader.cpp
index 1d866c6010..3e66456616 100644
--- a/gm/bitmapshader.cpp
+++ b/gm/bitmapshader.cpp
@@ -49,15 +49,15 @@ protected:
         draw_mask(&fMask);
     }
 
-    virtual SkString onShortName() {
+    SkString onShortName() override {
         return SkString("bitmapshaders");
     }
 
-    virtual SkISize onISize() {
+    SkISize onISize() override {
         return SkISize::Make(150, 100);
     }
 
-    virtual void onDraw(SkCanvas* canvas) {
+    void onDraw(SkCanvas* canvas) override {
         SkPaint paint;
 
         for (int i = 0; i < 2; i++) {