Add config options to run different GPU APIs to dm and nanobench

src/gpu/GrContextFactory.h

Index: src/gpu/GrContextFactory.h
diff --git a/src/gpu/GrContextFactory.h b/src/gpu/GrContextFactory.h
index 3a71d80a0aeb82495e872b98418e6a190ea3ff28..1a89c1d478531a45b36a770ba86fab67a4735e66 100644
--- a/src/gpu/GrContextFactory.h
+++ b/src/gpu/GrContextFactory.h
@@ -24,19 +24,21 @@
 class GrContextFactory : SkNoncopyable {
 public:
     enum GLContextType {
-        kNative_GLContextType,
+        kNative_GLContextType,  //! OpenGL or OpenGL ES context.
+        kGL_GLContextType,      //! OpenGL context.
+        kGLES_GLContextType,    //! OpenGL ES context.
 #if SK_ANGLE
-        kANGLE_GLContextType,
-        kANGLE_GL_GLContextType,
+        kANGLE_GLContextType,    //! ANGLE on DirectX OpenGL ES context.
+        kANGLE_GL_GLContextType, //! ANGLE on OpenGL OpenGL ES context.
 #endif
 #if SK_COMMAND_BUFFER
-        kCommandBuffer_GLContextType,
+        kCommandBuffer_GLContextType, //! Chromium command buffer OpenGL ES context.
 #endif
 #if SK_MESA
-        kMESA_GLContextType,
+        kMESA_GLContextType,  //! MESA OpenGL context
 #endif
-        kNull_GLContextType,
-        kDebug_GLContextType,
+        kNull_GLContextType,  //! Non-rendering OpenGL mock context.
+        kDebug_GLContextType, //! Non-rendering, state verifying OpenGL context.
         kLastGLContextType = kDebug_GLContextType
     };
 
@@ -124,14 +126,13 @@ public:
      * Get a context initialized with a type of GL context. It also makes the GL context current.
      * Pointer is valid until destroyContexts() is called.
      */
-    ContextInfo* getContextInfo(GLContextType type, GrGLStandard forcedGpuAPI = kNone_GrGLStandard, GLContextOptions options = kNone_GLContextOptions);
+    ContextInfo* getContextInfo(GLContextType type, GLContextOptions options = kNone_GLContextOptions);
 
     /**
      * Get a GrContext initialized with a type of GL context. It also makes the GL context current.
      */
-    GrContext* get(GLContextType type, GrGLStandard forcedGpuAPI = kNone_GrGLStandard,
-                   GLContextOptions options = kNone_GLContextOptions) {
-        if (ContextInfo* info = this->getContextInfo(type, forcedGpuAPI, options)) {
+    GrContext* get(GLContextType type, GLContextOptions options = kNone_GLContextOptions) {
+        if (ContextInfo* info = this->getContextInfo(type, options)) {
             return info->fGrContext;
         }
         return nullptr;