DM: also run benches once.

Also:
  - make GrMemoryPoolBenches threadsafe
  - some tweaks to various DM code
  - rename GM::shortName() to getName() to match benches and tests

On my desktop, (289 GMs, 617 benches) x 4 configs, 227 tests takes 46s in Debug, 14s in Release.  (Still minutes faster than running tests && bench && gm.)  GPU singlethreading is definitely the limiting factor again; going to reexamine whether that's helpful to thread it again.

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

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/178473006

git-svn-id: http://skia.googlecode.com/svn/trunk@13603 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/gm.cpp b/gm/gm.cpp
index 82dd476..803874f 100644
--- a/gm/gm.cpp
+++ b/gm/gm.cpp
@@ -40,7 +40,7 @@
     this->onDrawBackground(canvas);
 }
 
-const char* GM::shortName() {
+const char* GM::getName() {
     if (fShortName.size() == 0) {
         fShortName = this->onShortName();
     }