Add RGBA half float texture format.

src/gpu/gl/GrGLGpu.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrGLGpu.h"
 #include "GrGLStencilAttachment.h"
@@ skipping 2475 matching lines @@
                 }
                 *externalFormat = GR_GL_ALPHA;
             }
             if (kGL_GrGLStandard == this->glStandard() || this->glVersion() >= GR_GL_VER(3, 0)) {
                 *externalType = GR_GL_HALF_FLOAT;
             } else {
                 *externalType = GR_GL_HALF_FLOAT_OES;
             }
             break;
             
+        case kRGBA_half_GrPixelConfig:
+            *internalFormat = GR_GL_RGBA16F;
+            *externalFormat = GR_GL_RGBA;
+            if (kGL_GrGLStandard == this->glStandard() || this->glVersion() >= GR_GL_VER(3, 0)) {
+                *externalType = GR_GL_HALF_FLOAT;
+            } else {
+                *externalType = GR_GL_HALF_FLOAT_OES;
+            }
+            break;
+
         default:
             return false;
     }
     return true;
 }
 
 void GrGLGpu::setTextureUnit(int unit) {
     SkASSERT(unit >= 0 && unit < fHWBoundTextureUniqueIDs.count());
     if (unit != fHWActiveTextureUnitIdx) {
         GL_CALL(ActiveTexture(GR_GL_TEXTURE0 + unit));
@@ skipping 350 matching lines @@
             this->setVertexArrayID(gpu, 0);
         }
         int attrCount = gpu->glCaps().maxVertexAttributes();
         if (fDefaultVertexArrayAttribState.count() != attrCount) {
             fDefaultVertexArrayAttribState.resize(attrCount);
         }
         attribState = &fDefaultVertexArrayAttribState;
     }
     return attribState;
 }