Fix some warnings in ObjC code.

webrtc/api/objc/RTCOpenGLVideoRenderer.mm

 /*
  *  Copyright 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 130 matching lines @@
 static const GLsizei kNumTextureSets = 2;
 static const GLsizei kNumTextures = 3 * kNumTextureSets;
 
 @implementation RTCOpenGLVideoRenderer {
 #if TARGET_OS_IPHONE
   EAGLContext *_context;
 #else
   NSOpenGLContext *_context;
 #endif
   BOOL _isInitialized;
-  NSUInteger _currentTextureSet;
+  GLint _currentTextureSet;
   // Handles for OpenGL constructs.
   GLuint _textures[kNumTextures];
   GLuint _program;
 #if !TARGET_OS_IPHONE
   GLuint _vertexArray;
 #endif
   GLuint _vertexBuffer;
   GLint _position;
   GLint _texcoord;
   GLint _ySampler;
@@ skipping 144 matching lines @@
   return YES;
 }
 
 - (BOOL)updateTextureSizesForFrame:(RTCVideoFrame *)frame {
   if (frame.height == _lastDrawnFrame.height &&
       frame.width == _lastDrawnFrame.width &&
       frame.chromaWidth == _lastDrawnFrame.chromaWidth &&
       frame.chromaHeight == _lastDrawnFrame.chromaHeight) {
     return YES;
   }
-  GLsizei lumaWidth = frame.width;
-  GLsizei lumaHeight = frame.height;
-  GLsizei chromaWidth = frame.chromaWidth;
-  GLsizei chromaHeight = frame.chromaHeight;
+  GLsizei lumaWidth = static_cast<GLsizei>(frame.width);
+  GLsizei lumaHeight = static_cast<GLsizei>(frame.height);
+  GLsizei chromaWidth = static_cast<GLsizei>(frame.chromaWidth);
+  GLsizei chromaHeight = static_cast<GLsizei>(frame.chromaHeight);
   for (GLint i = 0; i < kNumTextureSets; i++) {
     glActiveTexture(GL_TEXTURE0 + i * 3);
     glTexImage2D(GL_TEXTURE_2D,
                  0,
                  RTC_PIXEL_FORMAT,
                  lumaWidth,
                  lumaHeight,
                  0,
                  RTC_PIXEL_FORMAT,
                  GL_UNSIGNED_BYTE,
@@ skipping 24 matching lines @@
       (NSUInteger)frame.vPitch != frame.chromaWidth) {
     _planeBuffer.reset(new uint8_t[frame.width * frame.height]);
   } else {
     _planeBuffer.reset();
   }
   return YES;
 }
 
 - (void)uploadPlane:(const uint8_t *)plane
             sampler:(GLint)sampler
-             offset:(NSUInteger)offset
+             offset:(GLint)offset
               width:(size_t)width
              height:(size_t)height
              stride:(int32_t)stride {
-  glActiveTexture(GL_TEXTURE0 + offset);
+  glActiveTexture(static_cast<GLenum>(GL_TEXTURE0 + offset));
   // When setting texture sampler uniforms, the texture index is used not
   // the texture handle.
   glUniform1i(sampler, offset);
 #if TARGET_OS_IPHONE
   BOOL hasUnpackRowLength = _context.API == kEAGLRenderingAPIOpenGLES3;
 #else
   BOOL hasUnpackRowLength = YES;
 #endif
   const uint8_t *uploadPlane = plane;
   if ((size_t)stride != width) {
    if (hasUnpackRowLength) {
       // GLES3 allows us to specify stride.
       glPixelStorei(GL_UNPACK_ROW_LENGTH, stride);
       glTexImage2D(GL_TEXTURE_2D,
                    0,
                    RTC_PIXEL_FORMAT,
-                   width,
-                   height,
+                   static_cast<GLsizei>(width),
+                   static_cast<GLsizei>(height),
                    0,
                    RTC_PIXEL_FORMAT,
                    GL_UNSIGNED_BYTE,
                    uploadPlane);
       glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
       return;
     } else {
       // Make an unpadded copy and upload that instead. Quick profiling showed
       // that this is faster than uploading row by row using glTexSubImage2D.
       uint8_t *unpaddedPlane = _planeBuffer.get();
       for (size_t y = 0; y < height; ++y) {
         memcpy(unpaddedPlane + y * width, plane + y * stride, width);
       }
       uploadPlane = unpaddedPlane;
     }
   }
   glTexImage2D(GL_TEXTURE_2D,
                0,
                RTC_PIXEL_FORMAT,
-               width,
-               height,
+               static_cast<GLsizei>(width),
+               static_cast<GLsizei>(height),
                0,
                RTC_PIXEL_FORMAT,
                GL_UNSIGNED_BYTE,
                uploadPlane);
 }
 
 - (BOOL)updateTextureDataForFrame:(RTCVideoFrame *)frame {
-  NSUInteger textureOffset = _currentTextureSet * 3;
+  GLint textureOffset = _currentTextureSet * 3;
   NSAssert(textureOffset + 3 <= kNumTextures, @"invalid offset");
 
   [self uploadPlane:frame.yPlane
             sampler:_ySampler
              offset:textureOffset
               width:frame.width
              height:frame.height
              stride:frame.yPitch];
 
   [self uploadPlane:frame.uPlane
@@ skipping 50 matching lines @@
                         GL_FLOAT,
                         GL_FALSE,
                         4 * sizeof(GLfloat),
                         (void *)(2 * sizeof(GLfloat)));
   glEnableVertexAttribArray(_texcoord);
 
   return YES;
 }
 
 @end