Remove FORMAT_RGB from gfx::PngCodec

media/gpu/rendering_helper.cc

Index: media/gpu/rendering_helper.cc
diff --git a/media/gpu/rendering_helper.cc b/media/gpu/rendering_helper.cc
index e6696ed9349f07da9711b6e1f782664e55e2f052..693daf2d18a34d9a95dee6da2adafc9c73899388 100644
--- a/media/gpu/rendering_helper.cc
+++ b/media/gpu/rendering_helper.cc
@@ -710,37 +710,20 @@ void RenderingHelper::Clear() {
   thumbnails_texture_id_ = 0;
 }
 
-void RenderingHelper::GetThumbnailsAsRGB(std::vector<unsigned char>* rgb,
-                                         bool* alpha_solid,
-                                         base::WaitableEvent* done) {
+void RenderingHelper::GetThumbnailsAsRGBA(std::vector<unsigned char>* rgba,
+                                          base::WaitableEvent* done) {
   CHECK(render_as_thumbnails_);
 
   const size_t num_pixels = thumbnails_fbo_size_.GetArea();
-  std::vector<unsigned char> rgba;
-  rgba.resize(num_pixels * 4);
+  rgba->resize(num_pixels * 4);
   glBindFramebufferEXT(GL_FRAMEBUFFER, thumbnails_fbo_id_);
   glPixelStorei(GL_PACK_ALIGNMENT, 1);
   // We can only count on GL_RGBA/GL_UNSIGNED_BYTE support.
-  glReadPixels(0, 0,
-               thumbnails_fbo_size_.width(), thumbnails_fbo_size_.height(),
-               GL_RGBA,
-               GL_UNSIGNED_BYTE,
-               &rgba[0]);
+  glReadPixels(0, 0, thumbnails_fbo_size_.width(),
+               thumbnails_fbo_size_.height(), GL_RGBA, GL_UNSIGNED_BYTE,
+               &(*rgba)[0]);
   glBindFramebufferEXT(GL_FRAMEBUFFER,
                        gl_surface_->GetBackingFramebufferObject());
-  rgb->resize(num_pixels * 3);
-  // Drop the alpha channel, but check as we go that it is all 0xff.
-  bool solid = true;
-  unsigned char* rgb_ptr = &((*rgb)[0]);
-  unsigned char* rgba_ptr = &rgba[0];
-  for (size_t i = 0; i < num_pixels; ++i) {
-    *rgb_ptr++ = *rgba_ptr++;
-    *rgb_ptr++ = *rgba_ptr++;
-    *rgb_ptr++ = *rgba_ptr++;
-    solid = solid && (*rgba_ptr == 0xff);
-    rgba_ptr++;
-  }
-  *alpha_solid = solid;
 
   done->Signal();
 }