Fix framebuffer completeness ES3 behavior.

gpu/command_buffer/service/framebuffer_manager.cc

Index: gpu/command_buffer/service/framebuffer_manager.cc
diff --git a/gpu/command_buffer/service/framebuffer_manager.cc b/gpu/command_buffer/service/framebuffer_manager.cc
index 173c2868ed0f1a3770478470c559d5c364bea40e..2798a5e2afd3c43d35816d7e5b596236c8ee530b 100644
--- a/gpu/command_buffer/service/framebuffer_manager.cc
+++ b/gpu/command_buffer/service/framebuffer_manager.cc
@@ -260,12 +260,14 @@ FramebufferManager::TextureDetachObserver::TextureDetachObserver() {}
 FramebufferManager::TextureDetachObserver::~TextureDetachObserver() {}
 
 FramebufferManager::FramebufferManager(
-    uint32 max_draw_buffers, uint32 max_color_attachments)
+    uint32 max_draw_buffers, uint32 max_color_attachments,
+    ContextGroup::ContextType context_type)
     : framebuffer_state_change_count_(1),
       framebuffer_count_(0),
       have_context_(true),
       max_draw_buffers_(max_draw_buffers),
-      max_color_attachments_(max_color_attachments) {
+      max_color_attachments_(max_color_attachments),
+      context_type_(context_type) {
   DCHECK_GT(max_draw_buffers_, 0u);
   DCHECK_GT(max_color_attachments_, 0u);
 }
@@ -476,7 +478,9 @@ GLenum Framebuffer::IsPossiblyComplete() const {
       if (width == 0 || height == 0) {
         return GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT;
       }
-    } else {
+    } else if (manager_->context_type() != ContextGroup::CONTEXT_TYPE_WEBGL2) {
+      // TODO(zmo): revisit this if we create ES3 contexts for clients other
+      // than WebGL 2.
       if (attachment->width() != width || attachment->height() != height) {
         return GL_FRAMEBUFFER_INCOMPLETE_DIMENSIONS_EXT;
       }