Revert of Add config options to run different GPU APIs to dm and nanobench (patchset #21 id:400001 of https://codereview.chromium.org/1490113005/ )

Reason for revert:
The Test-Win8-MSVC-ShuttleB-GPU-HD4600-x86_64-Debug builder fails after this CL.

Links to specific builds:
http://build.chromium.org/p/client.skia/builders/Test-Win8-MSVC-ShuttleB-GPU-HD4600-x86_64-Debug/builds/1689
http://build.chromium.org/p/client.skia/builders/Test-Win8-MSVC-ShuttleB-GPU-HD4600-x86_64-Debug/builds/1690
http://build.chromium.org/p/client.skia/builders/Test-Win8-MSVC-ShuttleB-GPU-HD4600-x86_64-Debug/builds/1691

Original issue's description:
> Add config options to run different GPU APIs to dm and nanobench
>
> Add extended config specification form that can be used to run different
> gpu backend with different APIs.
>
> The configs can be specified with the form:
> gpu(api=string,dit=bool,nvpr=bool,samples=int)
>
> This replaces and removes the --gpuAPI flag.
>
> All existing configs should still work.
>
> Adds following documentation:
>
> out/Debug/dm --help config
>
> Flags:
>     --config:	type: string	default: 565 8888 gpu nonrendering
>         Options: 565 8888 debug gpu gpudebug gpudft gpunull msaa16 msaa4
>         nonrendering null nullgpu nvprmsaa16 nvprmsaa4 pdf pdf_poppler skp svg
>         xps or use extended form 'backend(option=value,...)'.
>
>         Extended form: 'backend(option=value,...)'
>
>         Possible backends and options:
>
>         gpu(api=string,dit=bool,nvpr=bool,samples=int)	GPU backend
>         	api	type: string	default: native.
>         	    Select graphics API to use with gpu backend.
>         	    Options:
>         		native			Use platform default OpenGL or OpenGL ES backend.
>         		gl    			Use OpenGL.
>         		gles  			Use OpenGL ES.
>         		debug 			Use debug OpenGL.
>         		null  			Use null OpenGL.
>         	dit	type: bool	default: false.
>         	    Use device independent text.
>         	nvpr	type: bool	default: false.
>         	    Use NV_path_rendering OpenGL and OpenGL ES extension.
>         	samples	type: int	default: 0.
>         	    Use multisampling with N samples.
>
>         Predefined configs:
>
>         	gpu      	= gpu()
>         	msaa4    	= gpu(samples=4)
>         	msaa16   	= gpu(samples=16)
>         	nvprmsaa4	= gpu(nvpr=true,samples=4)
>         	nvprmsaa16	= gpu(nvpr=true,samples=16)
>         	gpudft    	= gpu(dit=true)
>         	gpudebug  	= gpu(api=debug)
>         	gpunull   	= gpu(api=null)
>         	debug     	= gpu(api=debug)
>         	nullgpu   	= gpu(api=null)
>
> BUG=skia:2992
>
> Committed: https://skia.googlesource.com/skia/+/e13ca329fca4c28cf4e078561f591ab27b743d23
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1490113005
>
> Committed: https://skia.googlesource.com/skia/+/c8b4336444e7b90382e04e33665fb3b8490b825b
>
> Committed: https://skia.googlesource.com/skia/+/9ebc3f0ee6db215dde461dc4777d85988cf272dd

TBR=mtklein@google.com,bsalomon@google.com,joshualitt@google.com,scroggo@google.com,kkinnunen@nvidia.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:2992

Review URL: https://codereview.chromium.org/1548683002
diff --git a/src/gpu/GrContextFactory.cpp b/src/gpu/GrContextFactory.cpp
index 4814e78..15af816 100755
--- a/src/gpu/GrContextFactory.cpp
+++ b/src/gpu/GrContextFactory.cpp
@@ -24,10 +24,13 @@
 #include "GrCaps.h"
 
 GrContextFactory::ContextInfo* GrContextFactory::getContextInfo(GLContextType type,
+                                                                GrGLStandard forcedGpuAPI,
                                                                 GLContextOptions options) {
     for (int i = 0; i < fContexts.count(); ++i) {
         if (fContexts[i]->fType == type &&
-            fContexts[i]->fOptions == options) {
+            fContexts[i]->fOptions == options &&
+            (forcedGpuAPI == kNone_GrGLStandard ||
+             forcedGpuAPI == fContexts[i]->fGLContext->gl()->fStandard)) {
             fContexts[i]->fGLContext->makeCurrent();
             return fContexts[i];
         }
@@ -36,39 +39,31 @@
     SkAutoTUnref<GrContext> grCtx;
     switch (type) {
         case kNative_GLContextType:
-            glCtx.reset(SkCreatePlatformGLContext(kNone_GrGLStandard));
+            glCtx.reset(SkCreatePlatformGLContext(forcedGpuAPI));
             break;
-        case kGL_GLContextType:
-            glCtx.reset(SkCreatePlatformGLContext(kGL_GrGLStandard));
-            break;
-        case kGLES_GLContextType:
-            glCtx.reset(SkCreatePlatformGLContext(kGLES_GrGLStandard));
-            break;
-#if SK_ANGLE
-#ifdef SK_BUILD_FOR_WIN
+#ifdef SK_ANGLE
         case kANGLE_GLContextType:
-            glCtx.reset(SkANGLEGLContext::CreateDirectX());
+            glCtx.reset(SkANGLEGLContext::Create(forcedGpuAPI, false));
             break;
-#endif
         case kANGLE_GL_GLContextType:
-            glCtx.reset(SkANGLEGLContext::CreateOpenGL());
+            glCtx.reset(SkANGLEGLContext::Create(forcedGpuAPI, true));
             break;
 #endif
-#if SK_COMMAND_BUFFER
+#ifdef SK_COMMAND_BUFFER
         case kCommandBuffer_GLContextType:
-            glCtx.reset(SkCommandBufferGLContext::Create());
+            glCtx.reset(SkCommandBufferGLContext::Create(forcedGpuAPI));
             break;
 #endif
-#if SK_MESA
+#ifdef SK_MESA
         case kMESA_GLContextType:
-            glCtx.reset(SkMesaGLContext::Create());
+            glCtx.reset(SkMesaGLContext::Create(forcedGpuAPI));
             break;
 #endif
         case kNull_GLContextType:
-            glCtx.reset(SkNullGLContext::Create());
+            glCtx.reset(SkNullGLContext::Create(forcedGpuAPI));
             break;
         case kDebug_GLContextType:
-            glCtx.reset(SkDebugGLContext::Create());
+            glCtx.reset(SkDebugGLContext::Create(forcedGpuAPI));
             break;
     }
     if (nullptr == glCtx.get()) {