Add ShaderBuilders to EmitArgs and remove gettings from ProgBuilder.

BUG=skia:

Review URL: https://codereview.chromium.org/1457543003
diff --git a/src/gpu/effects/GrConvexPolyEffect.cpp b/src/gpu/effects/GrConvexPolyEffect.cpp
index 69dbafd..13df7bc 100644
--- a/src/gpu/effects/GrConvexPolyEffect.cpp
+++ b/src/gpu/effects/GrConvexPolyEffect.cpp
@@ -111,32 +111,32 @@
                                        "rect",
                                        &rectName);
 
-    GrGLSLFragmentBuilder* fsBuilder = args.fBuilder->getFragmentShaderBuilder();
-    const char* fragmentPos = fsBuilder->fragmentPosition();
+    GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
+    const char* fragmentPos = fragBuilder->fragmentPosition();
     if (GrProcessorEdgeTypeIsAA(aare.getEdgeType())) {
         // The amount of coverage removed in x and y by the edges is computed as a pair of negative
         // numbers, xSub and ySub.
-        fsBuilder->codeAppend("\t\tfloat xSub, ySub;\n");
-        fsBuilder->codeAppendf("\t\txSub = min(%s.x - %s.x, 0.0);\n", fragmentPos, rectName);
-        fsBuilder->codeAppendf("\t\txSub += min(%s.z - %s.x, 0.0);\n", rectName, fragmentPos);
-        fsBuilder->codeAppendf("\t\tySub = min(%s.y - %s.y, 0.0);\n", fragmentPos, rectName);
-        fsBuilder->codeAppendf("\t\tySub += min(%s.w - %s.y, 0.0);\n", rectName, fragmentPos);
+        fragBuilder->codeAppend("\t\tfloat xSub, ySub;\n");
+        fragBuilder->codeAppendf("\t\txSub = min(%s.x - %s.x, 0.0);\n", fragmentPos, rectName);
+        fragBuilder->codeAppendf("\t\txSub += min(%s.z - %s.x, 0.0);\n", rectName, fragmentPos);
+        fragBuilder->codeAppendf("\t\tySub = min(%s.y - %s.y, 0.0);\n", fragmentPos, rectName);
+        fragBuilder->codeAppendf("\t\tySub += min(%s.w - %s.y, 0.0);\n", rectName, fragmentPos);
         // Now compute coverage in x and y and multiply them to get the fraction of the pixel
         // covered.
-        fsBuilder->codeAppendf("\t\tfloat alpha = (1.0 + max(xSub, -1.0)) * (1.0 + max(ySub, -1.0));\n");
+        fragBuilder->codeAppendf("\t\tfloat alpha = (1.0 + max(xSub, -1.0)) * (1.0 + max(ySub, -1.0));\n");
     } else {
-        fsBuilder->codeAppendf("\t\tfloat alpha = 1.0;\n");
-        fsBuilder->codeAppendf("\t\talpha *= (%s.x - %s.x) > -0.5 ? 1.0 : 0.0;\n", fragmentPos, rectName);
-        fsBuilder->codeAppendf("\t\talpha *= (%s.z - %s.x) > -0.5 ? 1.0 : 0.0;\n", rectName, fragmentPos);
-        fsBuilder->codeAppendf("\t\talpha *= (%s.y - %s.y) > -0.5 ? 1.0 : 0.0;\n", fragmentPos, rectName);
-        fsBuilder->codeAppendf("\t\talpha *= (%s.w - %s.y) > -0.5 ? 1.0 : 0.0;\n", rectName, fragmentPos);
+        fragBuilder->codeAppendf("\t\tfloat alpha = 1.0;\n");
+        fragBuilder->codeAppendf("\t\talpha *= (%s.x - %s.x) > -0.5 ? 1.0 : 0.0;\n", fragmentPos, rectName);
+        fragBuilder->codeAppendf("\t\talpha *= (%s.z - %s.x) > -0.5 ? 1.0 : 0.0;\n", rectName, fragmentPos);
+        fragBuilder->codeAppendf("\t\talpha *= (%s.y - %s.y) > -0.5 ? 1.0 : 0.0;\n", fragmentPos, rectName);
+        fragBuilder->codeAppendf("\t\talpha *= (%s.w - %s.y) > -0.5 ? 1.0 : 0.0;\n", rectName, fragmentPos);
     }
 
     if (GrProcessorEdgeTypeIsInverseFill(aare.getEdgeType())) {
-        fsBuilder->codeAppend("\t\talpha = 1.0 - alpha;\n");
+        fragBuilder->codeAppend("\t\talpha = 1.0 - alpha;\n");
     }
-    fsBuilder->codeAppendf("\t\t%s = %s;\n", args.fOutputColor,
-                           (GrGLSLExpr4(args.fInputColor) * GrGLSLExpr1("alpha")).c_str());
+    fragBuilder->codeAppendf("\t\t%s = %s;\n", args.fOutputColor,
+                             (GrGLSLExpr4(args.fInputColor) * GrGLSLExpr1("alpha")).c_str());
 }
 
 void GLAARectEffect::onSetData(const GrGLSLProgramDataManager& pdman,
@@ -197,26 +197,26 @@
                                              "edges",
                                             cpe.getEdgeCount(),
                                             &edgeArrayName);
-    GrGLSLFragmentBuilder* fsBuilder = args.fBuilder->getFragmentShaderBuilder();
-    fsBuilder->codeAppend("\t\tfloat alpha = 1.0;\n");
-    fsBuilder->codeAppend("\t\tfloat edge;\n");
-    const char* fragmentPos = fsBuilder->fragmentPosition();
+    GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
+    fragBuilder->codeAppend("\t\tfloat alpha = 1.0;\n");
+    fragBuilder->codeAppend("\t\tfloat edge;\n");
+    const char* fragmentPos = fragBuilder->fragmentPosition();
     for (int i = 0; i < cpe.getEdgeCount(); ++i) {
-        fsBuilder->codeAppendf("\t\tedge = dot(%s[%d], vec3(%s.x, %s.y, 1));\n",
-                               edgeArrayName, i, fragmentPos, fragmentPos);
+        fragBuilder->codeAppendf("\t\tedge = dot(%s[%d], vec3(%s.x, %s.y, 1));\n",
+                                 edgeArrayName, i, fragmentPos, fragmentPos);
         if (GrProcessorEdgeTypeIsAA(cpe.getEdgeType())) {
-            fsBuilder->codeAppend("\t\tedge = clamp(edge, 0.0, 1.0);\n");
+            fragBuilder->codeAppend("\t\tedge = clamp(edge, 0.0, 1.0);\n");
         } else {
-            fsBuilder->codeAppend("\t\tedge = edge >= 0.5 ? 1.0 : 0.0;\n");
+            fragBuilder->codeAppend("\t\tedge = edge >= 0.5 ? 1.0 : 0.0;\n");
         }
-        fsBuilder->codeAppend("\t\talpha *= edge;\n");
+        fragBuilder->codeAppend("\t\talpha *= edge;\n");
     }
 
     if (GrProcessorEdgeTypeIsInverseFill(cpe.getEdgeType())) {
-        fsBuilder->codeAppend("\talpha = 1.0 - alpha;\n");
+        fragBuilder->codeAppend("\talpha = 1.0 - alpha;\n");
     }
-    fsBuilder->codeAppendf("\t%s = %s;\n", args.fOutputColor,
-                           (GrGLSLExpr4(args.fInputColor) * GrGLSLExpr1("alpha")).c_str());
+    fragBuilder->codeAppendf("\t%s = %s;\n", args.fOutputColor,
+                             (GrGLSLExpr4(args.fInputColor) * GrGLSLExpr1("alpha")).c_str());
 }
 
 void GrGLConvexPolyEffect::onSetData(const GrGLSLProgramDataManager& pdman,