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, 30 insertions, 8 deletions

diff --git a/tools/flags/SkCommandLineFlags.h b/tools/flags/SkCommandLineFlags.h
index 5909413523..909718d3e7 100644
--- a/tools/flags/SkCommandLineFlags.h
+++ b/tools/flags/SkCommandLineFlags.h
@@ -76,6 +76,11 @@
  *  as its value. All strings that follow the flag on the command line (until
  *  a string that begins with '-') will be entries in the array.
  *
+ *  DEFINE_extended_string(args, .., .., extendedHelpString);
+ *
+ *  creates a similar string array flag as DEFINE_string. The flag will have extended help text
+ *  (extendedHelpString) that can the user can see with '--help <args>' flag.
+ *
  *  Any flag can be referenced from another file after using the following:
  *
  *  DECLARE_x(name);
@@ -114,6 +119,10 @@ public:
      */
     class StringArray {
     public:
+        StringArray() { }
+        explicit StringArray(const SkTArray<SkString>& strings)
+            : fStrings(strings) {
+        }
         const char* operator[](int i) const {
             SkASSERT(i >= 0 && i < fStrings.count());
             return fStrings[i].c_str();
@@ -204,7 +213,15 @@ SK_UNUSED static bool unused_##name = SkFlagInfo::CreateStringFlag(TO_STRING(nam
                                                                    nullptr,              \
                                                                    &FLAGS_##name,     \
                                                                    defaultValue,      \
-                                                                   helpString)
+                                                                   helpString, nullptr)
+#define DEFINE_extended_string(name, defaultValue, helpString, extendedHelpString) \
+SkCommandLineFlags::StringArray FLAGS_##name;                                      \
+SK_UNUSED static bool unused_##name = SkFlagInfo::CreateStringFlag(TO_STRING(name),   \
+                                                                   nullptr, \
+                                                                   &FLAGS_##name, \
+                                                                   defaultValue, \
+                                                                   helpString, \
+                                                                   extendedHelpString)
 
 // string2 allows specifying a short name. There is an assert that shortName
 // is only 1 character.
@@ -214,7 +231,7 @@ SK_UNUSED static bool unused_##name = SkFlagInfo::CreateStringFlag(TO_STRING(nam
                                                                    TO_STRING(shortName),  \
                                                                    &FLAGS_##name,         \
                                                                    defaultValue,          \
-                                                                   helpString)
+                                                                   helpString, nullptr)
 
 #define DECLARE_string(name) extern SkCommandLineFlags::StringArray FLAGS_##name;
 
@@ -273,7 +290,7 @@ public:
      */
     static bool CreateBoolFlag(const char* name, const char* shortName, bool* pBool,
                                bool defaultValue, const char* helpString) {
-        SkFlagInfo* info = new SkFlagInfo(name, shortName, kBool_FlagType, helpString);
+        SkFlagInfo* info = new SkFlagInfo(name, shortName, kBool_FlagType, helpString, nullptr);
         info->fBoolValue = pBool;
         *info->fBoolValue = info->fDefaultBool = defaultValue;
         return true;
@@ -287,14 +304,15 @@ public:
      */
     static bool CreateStringFlag(const char* name, const char* shortName,
                                  SkCommandLineFlags::StringArray* pStrings,
-                                 const char* defaultValue, const char* helpString);
+                                 const char* defaultValue, const char* helpString,
+                                 const char* extendedHelpString);
 
     /**
      *  See comments for CreateBoolFlag.
      */
     static bool CreateIntFlag(const char* name, int32_t* pInt,
                               int32_t defaultValue, const char* helpString) {
-        SkFlagInfo* info = new SkFlagInfo(name, nullptr, kInt_FlagType, helpString);
+        SkFlagInfo* info = new SkFlagInfo(name, nullptr, kInt_FlagType, helpString, nullptr);
         info->fIntValue = pInt;
         *info->fIntValue = info->fDefaultInt = defaultValue;
         return true;
@@ -302,7 +320,7 @@ public:
 
     static bool CreateIntFlag(const char* name, const char* shortName, int32_t* pInt,
                               int32_t defaultValue, const char* helpString) {
-        SkFlagInfo* info = new SkFlagInfo(name, shortName, kInt_FlagType, helpString);
+        SkFlagInfo* info = new SkFlagInfo(name, shortName, kInt_FlagType, helpString, nullptr);
         info->fIntValue = pInt;
         *info->fIntValue = info->fDefaultInt = defaultValue;
         return true;
@@ -313,7 +331,7 @@ public:
      */
     static bool CreateDoubleFlag(const char* name, double* pDouble,
                                  double defaultValue, const char* helpString) {
-        SkFlagInfo* info = new SkFlagInfo(name, nullptr, kDouble_FlagType, helpString);
+        SkFlagInfo* info = new SkFlagInfo(name, nullptr, kDouble_FlagType, helpString, nullptr);
         info->fDoubleValue = pDouble;
         *info->fDoubleValue = info->fDefaultDouble = defaultValue;
         return true;
@@ -383,6 +401,7 @@ public:
     const SkString& shortName() const { return fShortName; }
 
     const SkString& help() const { return fHelpString; }
+    const SkString& extendedHelp() const { return fExtendedHelpString; }
 
     SkString defaultValue() const {
         SkString result;
@@ -421,11 +440,13 @@ public:
     }
 
 private:
-    SkFlagInfo(const char* name, const char* shortName, FlagTypes type, const char* helpString)
+    SkFlagInfo(const char* name, const char* shortName, FlagTypes type, const char* helpString,
+               const char* extendedHelpString)
         : fName(name)
         , fShortName(shortName)
         , fFlagType(type)
         , fHelpString(helpString)
+        , fExtendedHelpString(extendedHelpString)
         , fBoolValue(nullptr)
         , fDefaultBool(false)
         , fIntValue(nullptr)
@@ -453,6 +474,7 @@ private:
     SkString             fShortName;
     FlagTypes            fFlagType;
     SkString             fHelpString;
+    SkString             fExtendedHelpString;
     bool*                fBoolValue;
     bool                 fDefaultBool;
     int32_t*             fIntValue;