Change comments about sized internal formats

src/gpu/gl/GrGpuGL.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 "GrGpuGL.h"
 #include "GrGLStencilBuffer.h"
@@ skipping 592 matching lines @@
         // 565 is not a sized internal format on desktop GL. So on desktop with
         // 565 we always use an unsized internal format to let the system pick
         // the best sized format to convert the 565 data to. Since TexStorage
         // only allows sized internal formats we will instead use TexImage2D.
         useTexStorage = desc.fConfig != kRGB_565_GrPixelConfig;
     }
 
     GrGLenum internalFormat;
     GrGLenum externalFormat;
     GrGLenum externalType;
-    // glTexStorage requires sized internal formats on both desktop and ES. ES
-    // glTexImage requires an unsized format.
+    // glTexStorage requires sized internal formats on both desktop and ES. ES2 requires an unsized
+    // format for glTexImage, unlike ES3 and desktop. However, we allow the driver to decide the
+    // size of the internal format whenever possible and so only use a sized internal format when
+    // using texture storage.
     if (!this->configToGLFormats(dataConfig, useTexStorage, &internalFormat,
                                  &externalFormat, &externalType)) {
         return false;
     }
 
     if (!isNewTexture && GR_GL_PALETTE8_RGBA8 == internalFormat) {
         // paletted textures cannot be updated
         return false;
     }
 
@@ skipping 177 matching lines @@
     // If we are using multisampling we will create two FBOS. We render to one and then resolve to
     // the texture bound to the other. The exception is the IMG multisample extension. With this
     // extension the texture is multisampled when rendered to and then auto-resolves it when it is
     // rendered from.
     if (desc->fSampleCnt > 0 && this->glCaps().usesMSAARenderBuffers()) {
         GL_CALL(GenFramebuffers(1, &desc->fRTFBOID));
         GL_CALL(GenRenderbuffers(1, &desc->fMSColorRenderbufferID));
         if (!desc->fRTFBOID ||
             !desc->fMSColorRenderbufferID ||
             !this->configToGLFormats(desc->fConfig,
-                                     // GLES requires sized internal formats
+                                     // ES2 and ES3 require sized internal formats for rb storage.
                                      kES_GrGLBinding == this->glBinding(),
                                      &msColorFormat,
                                      NULL,
                                      NULL)) {
             goto FAILED;
         }
     } else {
         desc->fRTFBOID = desc->fTexFBOID;
     }
 
@@ skipping 1729 matching lines @@
             this->setVertexArrayID(gpu, 0);
         }
         int attrCount = gpu->glCaps().maxVertexAttributes();
         if (fDefaultVertexArrayAttribState.count() != attrCount) {
             fDefaultVertexArrayAttribState.resize(attrCount);
         }
         attribState = &fDefaultVertexArrayAttribState;
     }
     return attribState;
 }