FBFetch refactor + arm support

src/gpu/gl/GrGLCaps.h

Index: src/gpu/gl/GrGLCaps.h
diff --git a/src/gpu/gl/GrGLCaps.h b/src/gpu/gl/GrGLCaps.h
index ccf04fd7ba5a3d668ef5d2671d0defc5af6ea6b6..bddc4d53f383af8e7421e4dd42f4ad51debf419a 100644
--- a/src/gpu/gl/GrGLCaps.h
+++ b/src/gpu/gl/GrGLCaps.h
@@ -74,8 +74,10 @@ public:
         kEXT_FBFetchType,
         /** GL_NV_shader_framebuffer_fetch */
         kNV_FBFetchType,
+        /** GL_ARM_shader_framebuffer_fetch */
+        kARM_FBFetchType,
 
-        kLast_FBFetchType = kNV_FBFetchType
+        kLast_FBFetchType = kARM_FBFetchType
     };
 
     enum InvalidateFBType {
@@ -174,8 +176,17 @@ public:
                kES_EXT_MsToTexture_MSFBOType == fMSFBOType;
     }
 
+    /**
+     * Some helper functions for encapsulating various extensions to read FB Buffer on openglES
+     *
+     * TODO On desktop opengl 4.2+ we can achieve something similar to this effect
+     */
     FBFetchType fbFetchType() const { return fFBFetchType; }
 
+    const char* fbFetchColorName() const { return fFBFetchColorName; }
+
+    const char* fbFetchExtensionString() const { return fFBFetchExtensionString; }
+
     InvalidateFBType invalidateFBType() const { return fInvalidateFBType; }
 
     /// What type of buffer mapping is supported?
@@ -341,6 +352,8 @@ private:
 
     MSFBOType           fMSFBOType;
     FBFetchType         fFBFetchType;
+    const char*	        fFBFetchColorName;
+    const char*	        fFBFetchExtensionString;
     InvalidateFBType    fInvalidateFBType;
     MapBufferType       fMapBufferType;
     LATCAlias           fLATCAlias;