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, 1 insertions, 1 deletions

diff --git a/samplecode/SampleManyRects.cpp b/samplecode/SampleManyRects.cpp
index 5032498b6a..a570853a03 100644
--- a/samplecode/SampleManyRects.cpp
+++ b/samplecode/SampleManyRects.cpp
@@ -34,7 +34,7 @@ protected:
         return this->INHERITED::onQuery(evt);
     }
 
-    virtual void onDrawContent(SkCanvas* canvas) {
+    void onDrawContent(SkCanvas* canvas) override {
         SkISize dsize = canvas->getDeviceSize();
         canvas->clear(0xFFF0E0F0);