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

Review URL: https://codereview.chromium.org/1490113005

1 files changed, 16 insertions, 1 deletions

diff --git a/include/core/SkString.h b/include/core/SkString.h
index 9229d808a6..93514f2659 100644
--- a/include/core/SkString.h
+++ b/include/core/SkString.h
@@ -267,7 +267,22 @@ template <> inline void SkTSwap(SkString& a, SkString& b) {
     a.swap(b);
 }
 
+enum SkStrSplitMode {
+    // Strictly return all results. If the input is ",," and the separator is ',' this will return
+    // an array of three empty strings.
+    kStrict_SkStrSplitMode,
+
+    // Only nonempty results will be added to the results. Multiple separators will be
+    // coalesced. Separators at the beginning and end of the input will be ignored.  If the input is
+    // ",," and the separator is ',', this will return an empty vector.
+    kCoalesce_SkStrSplitMode
+};
+
 // Split str on any characters in delimiters into out.  (Think, strtok with a sane API.)
-void SkStrSplit(const char* str, const char* delimiters, SkTArray<SkString>* out);
+void SkStrSplit(const char* str, const char* delimiters, SkStrSplitMode splitMode,
+                SkTArray<SkString>* out);
+inline void SkStrSplit(const char* str, const char* delimiters, SkTArray<SkString>* out) {
+    SkStrSplit(str, delimiters, kCoalesce_SkStrSplitMode, out);
+}
 
 #endif